Transfiguration

by SoSoft

First published

Rainbow offers herself as a volunteer to test the effects of Twilight's transformation potion.

Due to a consistent feeling of boredom for the past few months, Twilight has been developing a potion designed to reconfigure the body of the user.

Rainbow Dash happens to learn of this on the day she's looking for volunteers, and offers herself as a guinea pig to test the effects of the potion.

Twilight then makes sure it worked completely.


Massive thanks to MrSp33dy for proofreading, editing, and generally being an awesome human being...

Or at least, a being that somewhat amounts to the approximation of a human, you can never quite know with the Internet.

Guinea Pig

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Guinea Pig
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The sun shone brightly down on the blue pegasus as she flew through town. The air whipped against her features, it pushed against her wings and howled in her ears. She always enjoyed this feeling of being alive. Her heart beat rapidly as she pumped her wings faster and dipped below the roofs of the town. The adrenaline ripped through her veins as she tore passed pony after pony, kicking up a cloud of dust in her wake that spiralled and folded upon itself. She ignored the protests of the ponies that walked the streets; she wasn't low enough to collide with them anyway. Faster, she drove her wings. She sped like a dart through the air, completely in control. She closed her eyes briefly to delight in the feeling of the pure speed she's maintained.

"Watch out!" A cry pieced her reverie.

She quickly opened her eyes to find that she was about to crash into a pony attached to a wagon; the specifics were lost in the 'I better not crash into this' moment. Quickly, she jutted to the side, narrowly dodging the pony and the wagon of who knows what, probably also causing the unlucky pony to acquire a new hairstyle. She ignored the annoyed sound as she looked back at the obstacle she dodged.

'Heh... that was a close one' she then turned her head back forward to become face to face with a giant purple crystal tree. "Oh buck!" She was too close to slow down, so she quickly covered her face with her hooves to brace some of the blow; maybe she could break her forearms instead of the rest of her body. She tightly scrunched her eyes and clenched her jaw, bracing for the impact that she won't likely win.

It never came.

Cautiously, she opened her eyes. A purple haze overcame her vision as she levitated there, inches away from the solid crystal wall. She let out all the air in her lungs as she breathed a sigh of relief. She looked around to try and find the source of the purple haze. The sound of the front door opening caught her attentions.

Twilight Sparkle appeared in all nerdy princessy glory. Their eyes quickly met as Twilight pursed her lips. "Rainbow Dash,” she said, her tone more of a statement than a question, “what are you doing?"

"Uh... Trying not to die?" Rainbow shrugged as Twilight picked her up in her magic and lowered her to the ground.

"I would really have to assume the opposite judging by the way you were hurtling towards the castle," she shook her head as she placed her friend on the ground, "if it wasn't for my passive acceleration dampening array I placed around the castle, you'd be a Rainbow pancake."

Rainbow winced at the implications. She reached up behind her mane to scratch at the back of her head in an embarrassed manner, "Yeah... Sorry about that. What was that anyway?"

Twilight easily followed the segue, always excited to explain her projects, "Since you're interested, it is a passive acceleration dampening array, designed to continuously cover a certain area with two different types of fields, the primary deceleration array..."

Rainbow Dash nodded along, but quickly began to tune out the sound of Twilight's voice. Sure giant fields are impressive or whatever, but all this magical gibber gabber just flew right over her head. Twilight was so dug into explaining her force fields that she didn't notice Rainbow's disinterested wandering eyes.

Her eyes fell towards Twilight's wings, which hid saddlebags filled with stacks of papers. Interested in these papers Rainbow lifted a hoof to interrupt her lecturing friend, "Hey Twilight, whatcha got there?" She pointed to Twilight's saddlebags.

"What? Oh!" In her excitement of speaking about her magical discoveries, she had momentarily forgotten that she had something she needed to do, which included handing out the papers in her saddlebags, "these are flyers I'm going to hoof out to ponies in the town, I need a volunteer to test a new potion I have developed," She activated her magic to pull out one of the flyers, levitating it over to Rainbow, who quickly read through it once she got a hold of it, "It involves a lot of pain, so I don't expect many ponies would want to go through with it." Once Rainbow had taken the flyer, Twilight moved passed her to go into town.

"Ah huh... potion... magic... testing... blah blah blah," Rainbow tilted her head after she had finished reading, as if in thought, after a moment she shrugged, "Eh, I'll be your volunteer."

The sound of Rainbow's voice stopped Twilight in her tracks, she turned her head to look at Dash, "Really?"

Rainbow shrugged in response, "Yeah, sure, why not? I mean, I'm not doing anything, so I'm both free whenever and really bored," she flicked her head in the direction of the castle, "the only thing I've got going on is crashing into buildings, what do you need me to do?"

Twilight considered her friend for a moment, ‘as it turns out, willing test subjects do fall out of the sky,’ she thought with a smile. She looked back at Rainbow, "Thanks Dash, all I need you to do is come to the castle tomorrow at about three in the afternoon. You don't need to bring anything with you. I'll explain more once you're here."

Twilight then walked passed her and back into the castle. "Okay then, see ya tomorrow," Rainbow said.

"See you tomorrow, Dash... and thanks again!" Twilight replied as she closed the door behind her and disappeared into the castle.

Rainbow looked down back towards her flyer; she briefly scanned it for more details but quickly grew bored. She shrugged and flicked the paper behind her. She'll know more about it tomorrow when Twilight tells her about it, 'I mean, it's not going to be as bad as crashing headfirst into a giant mother bucking tree,' she thought, shaking her head, 'that's for sure.'

She flapped her wings to get in the air, and flew off to the fields outside of town. She may have an obligation tomorrow, but that's a whole day away, she has plenty of time for her to practice her not-flying-into-things flying.

.o0O0o.

Rainbow awoke bright and early the next day, which means she just managed to wake up before the afternoon. Such was this a rare occurrence that she actually managed to get her weather management done for the day, before her boss had to wake her up, surprising both the stallion and her colleagues.

All in all, this started out as a pretty good day for Rainbow. She managed to get her work done, so the sky was nice and clear with a smattering of clouds scattered about in preparation of the storm scheduled in a few days. Rainbow decided that the rest of the afternoon could be spent relaxing as opposed to being reckless like she usually is.

Besides, she wanted to make sure she was prepared for whatever Twilight had planned. She couldn't remember exactly what she read on the flyer, only the words potion and pain floated around her mind as lazily as the cloud upon which she currently rested.

Rainbow sighed as she relaxed further into the cloud she was laying on. She didn't want to fall asleep right now, as she didn't want to miss the deadline Twilight gave her, but the cloud was so soft, and the sun shone so pleasantly on her fur, warming her to the core. It became a real struggle to keep her eyes open.

Eventually, her eyes did slide to a close, her mind succumbing to the relief of not having to focus on anything in particular. The breeze played against her coat as it pushed on and danced with her cloud. It cooled her down to nicely contrast the warming sensation of the sun. She really didn't want to, but she was losing a very steep uphill battle against falling asleep. Her eyes dipped and her body relaxed, letting go of all the tensions she picked up when working. It was such a nice day today, and she should know, she made it that way.

Then she made the mistake of rolling over.

The clouds in the sky weren't big at all, hence 'smattering of clouds', and in her blissful journey into sleep Rainbow had forgotten that the cloud she was resting on was tantamount to a beanbag. So, as she tried to relax further and roll onto her stomach, she simply rolled and slid off the cloud.

Rainbow let out a quick yelp as she was rudely shocked awake. Her reflexes quickly activated, allowing her to right herself and begin flying. A shot of adrenaline spiked through her system, stinging her body from the inside. It ensured that she was woken up completly, if the fall didn't do that already.

She let out an annoyed groan as the adrenaline subsided, then shook her head to try and rid her mind of the pre-nap fog that had failed to take over her. She rubbed her eyes as she looked up to the sun to see if she could guess what time it was. Judging by its position in the sky, it was about two in the afternoon. She shrugged, "I might as well make my way to Twilight's," she said before setting off into a dive in the general direction of the castle.

She didn't push herself too hard, she just sped up enough to hear the wind softly cry in her ears and simply glided to the castle. It was only a few minutes of flight until she touched down outside the front door of the crystal tree and in front of the two guards posted to watch the door.

"Welcome to the castle ma'am, Princess Twilight isn't expecting you for another hour," the guard stated upon the sight of the prismatic pegasus.

"Eh, I figured I'd come around early," Rainbow shrugged it off and moved passed the guards. They parted their purple coloured spears and allowed her entrance. Her hooves echoed around the room as she walked along the hard crystal floors. She found herself wondering where Spike was, usually the little tyke was available to greet guests as they come to the door, no matter what he was doing.

'He must be out on an errand or something...' she then stopped in her movements, and looked around the massive empty halls of the crystal castle, 'where did Twilight want me to go again?

"Rainbow Dash!" Twilight's voice called from behind her, she overshot where she was supposed to go, Twilight was looking at her in wonder, "I wasn't expecting you so early."

Rainbow shrugged, "Eh, you know me, excited for science and stuff."

Twilight looked her up and down, before simply stating, "You fell off something you were napping on didn't you?"

Rainbow raised her eyebrow inquisitively, "Yeah, how did you know?"

"You're not as animated as you are usually, and you just said you were interested in science," Twilight shook her head and smiled, "which means you're tired and delusional, that and you just told me."

Rainbow pursed her lips, "You got me there."

Twilight rolled her eyes and motioned with a wing for Rainbow to follow. They walked for a bit; their doubled rhythmic hoofsteps gave some form of percussion to the empty halls of the crystal castle. The tattoo just bounced off the walls and danced with the newer sounds, all this just added to the stark emptiness of Twilight's castle.

Once they reached a seemingly random door, not far from where they started, Twilight opened the door and let Rainbow trot down the stairs behind it. Twilight then spoke, "I just have to finish setting up a few recording instruments then we can get started."

"Sure, how long should that take- Woah!" Rainbow's exclamation broke her sentence as the full room came in to view. This lab wasn't just different from the old one; it was massive! There were so many different machines scattered about in an orderly fashion, they were all shut off of course, but Rainbow could imagine all the sounds and lights that would fill the room if they were turned on. She didn't realise she was standing at the bottom of the stairs staring on in shock until Twilight broke her daze.

"You should have seen how I reacted when Princess Celestia informed me of my scientific allowance," as Twilight moved passed Rainbow, she softly nudged her with a wing to snap her out of her stupor. She pointed in a direction with the same wing, "Come on Rainbow, follow me, the testing area is ahead."

Rainbow nodded her head, letting the overwhelming feeling of all these machines pass her by. As they traversed through the metallic forest of machines, Rainbow briefly remarked on the different kinds of machines there were. There was one that looked like a microscope, except on steroids, another that looked like one of those super cool plasma ball things, and one that just looked like a refrigerator.

The sight of the refrigerator looking contraption confused her, "Hey, Twilight," she said to her friend, stopping their motion briefly, "what's that machine there?"

Twilight looked at Rainbow incredulously, then she smirked. She cleared her throat and explained exactly what that machine was, "It's a sealed container that uses a multi-cooling infused sapphire array to condense and evaporate the liquids inside, providing the items within a longer life before nutritional decay." Twilight then walked up to it, she put her hoof on the handle and pulled it back to open it.

A tiny delicate wave of coolness touched at Rainbow's hooves. She frowned once she realised what it was.

"It keeps my food cold."

"I know what a fridge is, gees, I was just... never mind."

Twilight laughed and shut the fridge door, "I'd offer you a sandwich, but I'm not sure that's wise." She continued walking, just to the door they were now close to. "Alright," Twilight began, falling into her scientist mode, "this is the room in which the experiment will take place, please enter and wait there for further instructions."

"Sure," Rainbow simply said.

"Oh, and I need this," Twilight gave little warning before she magically pulled a crimson strand of the pegasus' mane out of her head.

"Hey- ow! What was that for?" Rainbow raised her voice as she reached up se she could feel where the pain originated. Her reaction was more just to the shock of it than the actual severity.

"It's to finish off the potion, I just needed a strand of your DNA to complete it."

"A little warning would've been nice," she frowned, but moved passed Twilight to wait in the room. Twilight stuck her tongue out as she closed the door behind Rainbow. The room itself was very basic, the walls were bland and there were only two doors. The one she entered through and another one with the words 'Authorised Personal Only' printed in plain font on it. The floor also seemed to be slightly cushioned, it gave way slightly as Rainbow stepped, yet it didn't feel any different from the floor she was standing on before. It was some form of soft tile? Rainbow didn't know, nor care.

It was a short while before Twilight reappeared through the Authorised Personal door. She was wearing a white scientist cloak with safety goggles on her snout, she was also levitating a vial with some strange liquid in it. It was a very bright blue liquid, probably bluer than Rainbow's coat when the sun hit it directly.

Rainbow was about to ask her what it was before Twilight spoke up, still in her scientist mode, "Thank you for your participation in this experiment, would you like to know more about the experiment before we continue or are you well aware of the risks and dangers of this procedure?"

"I'd uh... like to know more please," Rainbow answered.

"Right," Twilight nodded, "what I currently hold in my magic is a vial containing an experimental potion designed to use a magical matrix to reconfigure the body of the drinker based on a modified strand of the user's DNA."

Rainbow imagined hearing several small explosions of sound; because the terminology flew over her head so fast it broke the sound barrier, twice. "It's a what to do what now?" was her intelligent response.

Twilight smiled at Rainbow's question, "It's a gender swapping potion."

Rainbow raised both her eyebrows in surprise and interest, "Really? So this will make me into a stallion?"

"Correct," Twilight nodded, "before I give you this to drink however, I need to inform you of the effects, risks and warnings about the potion."

"Shoot."

"First and foremost, this procedure involves a lot of pain, the potion sets about reconfiguring your bones and muscles, which also includes warping your nerve endings in your body, leading to intense pain," she waved the potion as if to acknowledge it, "this will also lead to your bones straining your muscles, which will cause them to become very sore afterwards."

Rainbow considered the dangers, before shrugging, pain wasn't something she was new to.

"Once you ingest the potion, it will sting your throat and head before causing you to become very disorientated and dazed, this is expected, the first thing it sets about changing is the chemical make up of the brain for the preliminary changes. It will then begin changing the physical aspects of your body, starting with the head and ending down at your flank," Twilight locked eyes with Rainbow, making sure the next part of her speech was seen as completely serious, "this is the start of the transformation process, which will cause a lot of, if not, tremendous pain. After hearing about these risks, do you still want to proceed with the experiment?"

Rainbow thought about her answer, on the one hoof, excruciating pain sucks big time, but on the other hoof, she's always been a bit curious about what it would be like to be a stallion, she had a small part of her brain wondering what it felt like to be the one entering, as opposed to being the one entered. She shrugged once more, having made up her mind, "Sure, hit me with it."

"Alright, allow me to set up various recording devices so I can monitor your vitals," Twilight then levitated three different objects into Rainbow's sight, one that looks like a headband, one that looked like it fits on her wrist and one that looked like a necklace. Each of them had a certain colour of crystal embedded in it, and the crystals all had a sheen to them that gave off their state of being enchanted. Twilight then put the bands where Rainbow had originally believed they would go, the wrist one levitated to her front right hoof, the necklace came apart so it can wrap around her neck and be secured easily, and the headband simply slipped over her head.

Once everything was secured, they all seemed to let off an audible beep of some kind, likely to let Twilight know that everything was working well. Once she was sure that they were in place and collecting data, Twilight levitated the vial of transfiguration potion to Rainbow's hoof. She then moved to one of the corners of the room, "Once the transformation stages begin, your muscles will seemingly begin to spasm, causing you to thrash about, I will be here to make sure you don't injure yourself too badly. Whenever you're ready Rainbow, you may drink the potion."

Rainbow nodded, then she used her teeth to remove the vial's lid. She briefly let air into her nose, causing her to smell an odd sent of vanilla mixed with blueberries or something. "Welp," Rainbow said, "bottoms up." She tipped the vial into her mouth and drank the potion.

As soon as the potion hit the back of her throat, it began to sharply sting. She couldn't help but cough as the stinging feeling overwhelmed her mouth and throat. The stinging then transformed into a headache as her brain felt like a flood of fog was rolling in. She blinked, and the world seemed to defocus around her, she moved her eyes, but they wouldn't lock on to anything. A smear of purple flew across her vision as she vaguely remembered Twilight's position.

"Woow... You were right," Rainbow slurred her speech as she slowly became unconnected with the world, "this does feel w-" she coughed again, her brain, head and throat suddenly lit up in agonising pain, as if her head had just combusted. She let out a strained yelp as the pain overcame her mind and upper body. The pain then quickly spread down to the rest of her body, lighting up her nerves with fire. She no longer had full control over her muscles, so she fell to the floor. In the period of three seconds after her speech was interrupted, she was on the floor, writhing in agony.

Twilight had to work extra hard to make sure that Rainbow didn't do any permanent damage to her body before it could finish changing. As she thrashed about, Twilight used her fine control of telekinesis to make sure that Rainbow's movements were slowed, so that if she were to swing her foreleg to the floor, instead of breaking the bone due to the speed, it would just press against the ground. It took a good majority of Twilight's concentration to keep her from hurting herself, she was thankful that she had the foresight to enchant the floor to make it more rubberised, otherwise Rainbow would have hurt herself very badly by now.

Then, an aching pain unlike anything Rainbow had felt before or was currently feeling entrapped her head. The transformation stage had started. Sounds of bone creaking and warping filled the pegasus' mind, as her nose, jaw, and cranium began to feel especially painful. They felt like they were moving on their own, but also like they were being constricted by her spasming face muscles. Twilight's telekineses moved into Rainbow's jaw, to hopefully prevent the strength of her clenching jaw from breaking her teeth.

Her facial features had stopped changing, leaving the muscles unable to function, her eyes and mouth dropped loosely and uncontrolled, she couldn't move those muscles, but she was still very much awake and aware of the changes that are now happening to her chest and forelegs. She felt like she was breathing in, but the breath moved way passed what she should have been able to do, she felt almost like her chest was inflating like a balloon. Her ribcage was warping and re-configuring itself to show a more powerful shape, it became more bull-like as opposed to swan-like. Her legs followed along with this change, slightly growing longer and thicker. Becoming stronger and more stallion-like to add to the bull-likeness of her chest. They finished their changes and became limp, the muscles having used up all their energy.

Once her chest and legs stopped changing, her back started cracking. Each of her vertebrae began to push against one another as they expanded and straightened, allowing for the ability to bolster a larger frame. After her spine, her wings were next. They began to strain themselves, twisting into painful positions as the muscles inside them thrashed about. Her fragile wing bones began to grow, spreading out further and growing thicker. Allowing her new wings to be able to hold a larger body in the sky.

Her flank and hindlegs then joined in on the changes, following her front legs and chest in growing longer and thicker, and less mare-like. It lost its petite frame and swan-shaped curves as it grew slightly to match the rest of her body with her now stallion-esque shape. Once her flank and hindlegs finished their changes, her crotch began to feel very painful.

Her teats felt strained, they felt like they were getting pulled as they shrank and were replaced by skin no different from the rest of her body. The following sensation was even stranger, pain flared up in her lower body where her ovaries were as they crushed and reformed, travelling down her body to just at the end of her closing vagina.

She could feel that skin begin to stretch and grow as the eggs that were once inside her ovaries began to repurpose themselves into sperm producing proteins. They separated into two distinct feelings in her crotch. When they started to grow, they began as no bigger than the size of peas. The skin that was covering them stretched, and became a darker colour, letting the growing testicles fall and sit in its hammock like form.

The growth wasn't stopping, her new testicles pushed against the skin, spurring on another stretch to hold them better. After a few more spurts of this, the growing began to slow as the last of her ovaries found their way into her new gene containing orbs. The skin holding them sagged once more, stretching to better hold the impressively sized additions.

Then a mix of overwhelming pain and pleasure flared up from her now-closed vagina. The feeling amplified as her clitoris shifted to just above the testicles and began to expand. It grew outwards and became longer. The appendage added inch after inch, then began to add thickness to itself. The exposed skin on her elongated clitoris became slightly harder and less sensitive to form what more resembles a stallion's penis. It hasn't stopped growing, it got thicker, causing the pleasure to increase passed the threshold of pain, Rainbow's wails of agony quickly shifted to groans of pleasure mixed with pain.

She had only then realised that sometime during her thrashing about, she landed on her stomach, she became aware of this through the kiss of cold flooring on her sensitive growing addition. She could feel it pressing against the floor, making it sink while pushing herself up as it increased in thickness and length. The muscles inside her new penis flexed and ached as the last of its growth pulsed and gradually slowed. She was left on the floor, panting with exhaustion.

Then, as quickly as the pain started, it vanished, and Rainbow was left on the floor. He was dead to the world. The full implications had yet to hit her tired mind. She just preferred to sleep over realising that she is now a he in many aspects. Her breathing slowed as he gave in to the misty-unawareness that is her slipping consciousness. She let her pulsing heart be his metronome, a beat she could use to drift off into a blissful serenity.

The world faded around her as he drifted off to sleep.

.o0O0o.

An uncomfortable, yet not unwelcome feeling came over Twilight as she had witnessed her friend's growing stallionhood. She imagined the feeling of that gigantic phallus penetrating her over and over, causing her mind to reel in imagined pleasure. She really wasn't expecting it to be that large. The slowly silencing scientific section of her brain drew the probable conclusion that Rainbow's latent magical energy could be heightened due to her connection to the Elements of Harmony.

The quick deduction snapped her mind back to the task at hoof and away from lust filled fantasies involving a certain newly formed stallion. She shook her head to clear away the last of the clouds in her mind and moved to pick her friend up in her magic, removing the recording devices as she did so.

Stallion in magical tow, she made her way out of the laboratory and down the hall of the castle to get to the guest bedroom. She gently placed Rainbow in the bed and tucked her in comfortably. Her exhaustion letting her continue her blissful rest undisturbed through the movement, as her new body recovered from the painful transformation.

Twilight looked at the form of her exhausted friend, and noted the complexity and size of her new body. As pleasurable as being penetrated relentlessly by an enormous cock might be, Twilight had something more orgasmic to set her mind to; finalizing the experiment evaluation! So with a flick of her horn, she summoned her designated clipboard with the potion notes already inscribed. She then levitated one of the quills from her lab coat and set to work outlining the results.

Rainbow, was a very good guinea pig.

Experiment Successful

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Experiment Successful
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Rainbow's mind warped as she slowly found himself drifting awake. She vaguely felt his head turn but the world shifted in the opposite direction, mocking the movement, sending his whole body into a world of discomfort and disconnection. Her head seemed to rest on a pillow, his body was covered by fabric on all sides. It would not respond to his mind's commands though, it felt as though she was disconnected and simply going for a nauseating ride. His head swayed in place and her body fell deeper into the fabric.

'That must have been some party...' one part of her mind laughed, the sound echoing in her flittering consciousness. It wasn't like that though, his body was wrong and her mind was swimming in an endless sea of warping waves and crushing swirls. She almost wished his brain was simply lit with the fire of a hangover; that would've been so much easier to deal with. Now though, her mind felt as though it was trying to stay afloat, struggling and gasping for breath.

Through the haze, she gradually became aware of his body. She didn't want to focus too hard, because he felt as though thinking too hard would end up making her mind fall too far, unable to resurface. He mentally touched over his body, as much as he could feel in the cocoon of fabric that entrapped her. His body felt... ballooned... as if it was touching more fabric than it was supposed to; it felt as though his body was larger than she remembered.

A sound cut through the sea of confusion. It was an anchor that fell right next to her, so he latched onto it so he could stay in the one place for now. He was carried into the sound that followed, a voice.

"Rainbow Dash? How are you feeling?" The sound was almost sickeningly sweet, though muffled by the fog contained within his head. It took a few moments, but eventually his brain managed to decode that muffled speech and relay to him that the voice belonged to Twilight, and that she asked her a question.

Rainbow tried his best to respond, but the sounds of her voice became lost, both in her limited ability to command his body and in the fabric that was pushed up against his face. As her voice broke free of his mouth, the mumble it was, he lightly remarked that her voice sounded different, he could feel it in her chest; it was deeper than usual. Somehow the message got across, whatever it was.

"That's to be expected, right now your brain is undergoing the process of ridding your body of any female hormones remaining in your system," Twilight's voice replied, "You've been asleep for about 14 hours now, but it's probably a good idea to go back to sleep for another few hours. I'm going to cast a sleep spell on you to help you fall asleep through the pain, okay?"

A grunt escaped Rainbow's throat and fell into his fabric prison.

"All right, you may feel a slight tingling sensation in your head for the next few..." The last of Twilight's speech faded with his consciousness, but, as one last fleeting glance into clarity, his mind remarked upon Twilight's presence. Amidst the haze, it felt as though Twilight was making her feel different inside, it was something to do with her voice, or the way she smelled. Before he could think about it any longer, her mind fell and his body relaxed as he finally let herself go, to be washed away by the sea into blissful serenity.

.o0O0o.

The next time he awoke, he was far more aware and in far better condition. His mind was no longer warping, and his body only ached as if he'd run a marathon a few days ago, it was a very familiar ache that he didn't really mind all that much.

Suddenly, his nose caught something in the air, something sweet and alluring. Something that made his mouth water with anticipation. It was musky, and salty, it felt warm in his nose. It woke him up completely, aroused him from his slumber. He shivered in anticipation as the compelling scent awoken something unknown inside of him, some kind of ravenous hunger. He wanted to find the source of the delicious smell and devour it for all it was worth.

It was hay bacon, he could definitely smell hay bacon.

"Good morning sleepy head," Twilight's voice entered his mind, "you've slept for a total of 20 hours, I figured you might be hungry."

He opened his mouth to give a response, but it was not needed, his stomach had already cut to the chase by letting out a loud growl. Twilight giggled at the sound, she levitated the tray of hay burgers over to where Rainbow Dash lay. He sat up slowly, as to not aggravate the ache in his muscles any more than he needed to. As soon as the tray of burgers landed on the sheets he quickly picked up the first of five burgers and set on devouring the greasy goodness. He let out a moan as the mouth-watering taste of a quarter pound of vegetable patty seised his tongue.

"So, as far as I can tell, the transformation was a success, it seems as though there are no negative effects during or after the process. As for now, there are three more things I need to finalise before I label this experiment as a success, starting with a short psychological evaluation. So, tell me Rainbow Dash," Twilight said as she levitated up a quill and the clipboard with all her notes, "how do you feel?"

He was taken back by what Twilight had said, 'Transformation? What tran- Oh right!' suddenly, the memories of the previous day's events flooded into his mind, along with the feeling of pain and the realisation of his change. He wanted to see the change for himself, but he couldn't really move as he wanted to at the moment, due to him not wanting to disrupt the Celestia-sent burgers in his lap, but he was able to just feel himself with his mind for a moment. He definitely felt... well... bigger than usual, and also he could feel something extra between his legs. He didn't want to get too excited yet, but if it was what he thought it was, he was going to be very happy. He then noticed, that throughout his entire examination of himself, he didn't really consider himself any part female any more. He remembered the feeling of confusion he felt earlier, when he just woke up, but now his mind was definitely certain, he was now a dude, no questions about it.

He pondered Twilight's question for a few moments as he chewed on his burger, eventually, he swallowed his mouthful and began to speak, "I don't know I-"

He coughed and became confused for a moment at the sound of his voice, it was way deeper than usual, and it didn't have that feminine quality that it used to have. He cleared his throat and spoke again, testing his new voice, "Hello? Hello. Hellllooooooo..." He said the last hello in his deepest voice, dragging out the syllables to really hear the extent of the change. He laughed at the sound, he looked over to Twilight to see that she had pursed her lips and narrowed her eyes at him, waiting for him to answer the question. He cleared his throat, "I don't know, I don't feel too different from before, a little larger I guess?"

'A little larger is not what I'd say,' Twilight thought as she scribbled away on her clipboard. "Ah huh, any pain or discomfort, especially in the head?"

The final bite was taken from the first burger, "My head feels fine, but the rest of my body? A little sore, but it's not too bad, it's the same kind of ache I get from exercising, no biggie." He swiftly moved on to start on eating the second burger as the sounds of a scratching quill filled the room.

"Okay, what about my presence here, do you think that you feel any different towards me now than you did before?"

"Hmm..." Rainbow hummed around his burger, he took the time to really look into his friend. He saw the way she was sitting, plot to the floor, tail curled neatly over her hind legs, left forearm bracing the ground, and her right forearm positioned so her head was leaning on her hoof, in the adorkable style Twilight is famous for. All of this was compounded by the lab coat she was wearing, he realised that she actually looked... very attractive; she was ridiculously attractive. It was something to do with the way her legs and tail were positioned, or the way her hair fell just above her eyes to give her the kind of accents in her eyes that displayed a certain amount of insecurity bolstered by an amazing intellect. He fell into a daze as he stared at Twilight for a while, not realising that he had his mouth open in a very unflattering way, and that the sauces in the burger were starting to drip.

The sensation of sauce hitting his barrel from his mouth shocked him out of his inspections, he quickly swallowed the bite before answering, "Wow... I don't think I felt this about you before, but holy Luna you are sexy Twilight," Twilight's ears tweaked when she heard that, her eyes shifted away from the clipboard and at Rainbow as she silently demanded elaboration. Rainbow continued, "You have this quality about you that screams I'm a nerd, but also whispers I'm a sexy beast, like I'll take you to my room and let you ravage me sort of sexy beast, and sweet Celestia I now know what it feels like to have a boner." The tray of burgers shifted on his lap as his hardening addition pushed against it from under the covers, he looked towards the bulge in the covers with his eyebrows raised, the slightly uncomfortable feeling of being aroused journeyed into his mind from the base of his stomach.

Twilight looked away from Rainbow and back to her notes, her cheeks lighting on fire from his explanation. "Uhh... Thanks, I guess?" She said as she busied herself with writing out what he said.

"No sweat," he shrugged and went back to finishing off his second burger before moving onto the third, he was still very hungry after all. The feeling of his boner still piqued at the edge of his consciousness though, but it was put aside for now in favour of the delicious food in front of him. Honestly, it did feel a bit uncomfortable being bunched beneath the covers of the bed and the tray. He shifted the tray slightly when he picked up his third burger, and it moved along his penis, causing the sensitive tool to flex, activating a muscle that Rainbow had never felt before. It was pleasurable, but it also slightly ached.

Once Twilight had finished with the questions, she cleared her throat and brought up the next part of her analysis, "Okay, now I need to take some measurements, just to see the extent of the physical changes, stretch out your hoof please."

Rainbow did as instructed, showing her his left hoof, while keeping the burger in his right. A tape measure, likely borrowed from Rarity, floated out from wherever Twilight was keeping it and snaked its way to Rainbow's arm. She read the measurement off the tape and wrote down the difference, "It seems your foreleg is about 5 inches longer than before, now for the diameter at various parts on your leg." The tape wrapped around the tip of his hoof, his wrist, his elbow joint, and just before the shoulder joint. After the measurements were written down she did a few calculations and recited the results, "There seems to be a fairly even growth around the foreleg of about 1 to 2.5 inches, leading to an average of 1.8 more inches to the diameter of your leg."

Rainbow nodded, though not really caring about the exact dimensions of his foreleg, to be honest, he was more concerned with the dimensions of a certain fifth leg he'd acquired. He took the last bite to the third burger and moved to the forth. Twilight wanted him to sit up a bit more and turn his back to her so she could access his back and wings. She remarked on more of his sizes but he had tuned her voice out in favour of the second last burger in his hooves. He was honestly quite impressed at the amount he had eaten, when he had a mare's body, three full size hay burgers like these would be a challenge, but he had just demolished three and was moving onto the fourth with no problems.

"And last but not least, I need you to lower the covers so I can measure your hind legs," Twilight cut through his tuning out, she levitated the tray with the last burger on it away from his lap to allow him to comply. He lowered the covers with ne'er a thought, exposing his lower body. Being measured and treated like a test subject wasn't really all that arousing, so his penis had retracted into his sheath in the meantime.

After the measuring tape moved about his hind legs a lot like how it did to his foreleg, and Twilight had got what she needed, she ran the calculations to find out just how much bigger Rainbow had become. "Well, judging by my calculations, you should stand at least 10 to 12 inches taller than before, with your overall body depth and width increasing by about 6 inches. All in all, your body seemed to experience a mean increase of about 19.63742 percent, or about twenty percent if you want to round." Rainbow had finished his fourth burger, and wanted to move on to the last burger, but because Twilight levitated the tray out of the way, he couldn't reach it. He let out a sorrowful whine as he tried to reach across in vain to it.

Twilight ignored him though, and moved on to the next part of her measurements. "Okay, now to move on to the size of your, well, additions," she cleared her throat and commanded him to allow her easier access, "I need you to sit facing me."

He sighed and looked with longing at the remaining burger, but he complied to Twilight's instructions. Once he was seated facing Twilight, she pressed the tape against his testicles. He could feel the slight tingling of magic against his sensitive orbs as she levitated the tape close to them, "Okay," she leaned in to try and get a better reading, "It seems that your testicles together have a total width of about 3 and a half inches, leading me to assume that each testicle is..." she trailed off as she breathed deeply, she exhaled with a sound, "Whoh, there's no doubt that you smell like a stallion, your musk is a bit... a bit intoxicating." She shook her head, a blush adorning her cheeks "Anyway, the total width leads me to assume that each testicle is about 1.5 inches in diameter."

Finally finding out exactly how big his additions were was really turning Rainbow on, again he could feel the aching of his penis coming alive and becoming hard. He shifted a bit where he sat, 'Gees, this thing is insistent' he thought to himself, a blush from the exposure finding its way to his cheeks.

"I'm not a Biology major," Twilight continued, unabated by Rainbow's movements, "but if my calculations are correct, barring any abnormality within the transformation, and without looking directly at any ejaculate, you should release anywhere between..." Twilight's eyes slightly glazed as she ran the numbers over in her mind, three times to make sure, "600 and 900 million sperm per release."

"Whoa," Rainbow said, blanching at the number, but not really understanding the implications, "that's a lot right?"

"It's twice the average amount," she nodded, 'The elements of harmony really did have a great effect on her transformation. It's time for the main question to be answered,' she thought slyly to herself. She cleared her throat, "Now," she said aloud, directing Rainbow's attention towards her once more, "I must get the measurements of your shaft to complete the physical changes section of the evaluation. In order to do this, I need you to be fully erect, so..." she lowered her voice as she stepped closer to the stallion on the bed, she gingerly climbed up onto the bed and over the stallion. She narrowed her eyes as she looked into the stallion's. Positioned over him like she was, she could really feel the difference the transformation had on her friend, she could feel the power hiding underneath his pelt, the strength in his new muscles, it sent a shiver down her spine as her touch sent a shiver down his. She leaned in close to him, lowering herself so she was close to his ears, she whispered the rest of her speech in the sultriest voice she could manage, "... I need to see how far your attraction to me goes."

Rainbow looked into her eyes when she lifted her head again, he was excited, intimidated, embarrassed and slightly uncomfortable all at once from at Twilight's proximity and her warm breath tickling his ears. When Twilight came close to him, he couldn't help but breath in her scent. She smelled really nice, it was a lavender scent that was mixed with a hint of her arousal. It definitely did the trick of turning him on, but if Twilight didn't believe that he was, she made it certain by her next action. She, slowly, moved lower down Rainbow's body, allowing her body to lightly graze against his throbbing erection, causing it to flex with every touch of her fur. Twilight continued to lock eyes with Rainbow as she moved, letting a small grin grace her lips from Rainbow's reactions.

After an eternity for him, Twilight found her way to the tip of his hardening penis. She planted a little kiss on it, which made Rainbow close his eyes and let out a small moan. She then moved further down, navigating to the base of his shaft, gently nuzzling it as she went. When she finally made it, she did something that made his breath catch. She closed her eyes and dipped her tongue out, she then touched it to the base of his shaft, and slowly dragged it upwards to the tip. For every second she travelled, she lightly caressed his testicles with her hooves, massaging them as she travelled up his massive shaft that got even harder by the second. She stopped at the halfway point to wrap her tongue as far as she could around his thickness, but of course, due to the size, her tongue didn't get far. She opened her eyes and looked into Rainbow's. He shuddered as she did so, causing her to giggle at the effect she was having on him. She gave his medial ring a light kiss before resuming her tongue's journey to the tip, never letting his balls go un-massaged.

It took a torturously long time for Twilight to finish her journey, she kissed his tip again once she made it to the top. Then she forwent massaging his hanging orbs and wrapped both her hooves around his cock. She leaned back and pulled it towards her slightly, causing Rainbow to close his eyes and let out a very deep and low groan of pleasure. Once he settled again, she locked eyes with him and gently sucked on the head of his penis, drawing it into her mouth. Once she managed to stretch her jaw around the tip, she pushed down a couple of inches. She savoured the taste of the stallion for a moment, while not letting her eyes drift from his. After a while of staying static, she began to bob her head up and down. The action caused an immediate reaction from Rainbow, he arched his back due to the pleasure and let out a very loud moan.

Twilight continued her ministrations, every time she dipped her head she traveled further down the giant dick. Her saliva coated the first few inches of his penis, allowing her to move her head more smoothly and enabling her to reach further down his dick. Eventually, she managed to reach the point where his tip pressed against her uvula, she scrunched her eyes closed as she fought against her gag reflex. Once she managed to calm herself down, she opened her eyes.

His medial ring was still a few inches away.

She moaned at the implication that she wouldn't even be able to completely swallow his cock due to its massive size. Rainbow reciprocated the noise, her throat vibrated in her groan, causing the sensation to release all kinds of pleasure into the mind of the stallion. Eventually, after staying there for a while, Twilight slowly dragged up his shaft. Letting the hunk of meat fall out of her mouth. She breathed in, replenishing her supply of oxygen.

"Alright," she said, her voice slightly croaky, "I believe I have you hard enough, just let me..." she levitated the clipboard and measuring tape up once again, quickly setting about measuring the dimensions of his throbbing erection. The tape first rolled down his shaft, reading the total length of it from his scrotum to the tip, she wrote down the two digits with a shudder of anticipation. The tape then snaked its way to wrap around the base of his shaft, then the area just before the medial ring, the medial ring itself, and finally, the area just below the tip. Each time the tape wrapped around his hard shaft and moved, the feeling of lust and need grew larger in Rainbow's mind. It was driving him mental.

"Well, Twi'? How big am I?" Rainbow asked her, his tone becoming ragged and rushed as the pain of his bluing balls became apparent. His eyes opened wide at the amount of discomfort he felt from the air caressing his wet shaft, his dick flexed at the feeling. He found himself wanting to jump off the bed, tackle Twilight to the floor and relentlessly fuck her until he could release. He didn't understand just how powerful that feeling was when he was a mare. When meeting with her friends at the bar, she'd always overhear stallions complain about being 'blue-balled'. He never really understood why stallions would complain about it so much, but after he felt what they were complaining about, he knew it was indeed, the worst.

"Right, well, the thickness of your shaft at the base is about 2.5 inches in diameter, it then extends to 2.3 by your medial ring, which has a thickness of 2.4 inches, then, at the top it is 2 inches thick," as she was narrating the dimensions, she pointed at the areas the mentioned, causing Rainbow's sensitive shaft to flex every time. "As for the length," she continued, "from base to mid is about 6.5 inches, and from mid to tip is about 6 inches, the entire thing is 12.6 inches long, give or take."

"Really?" Rainbow said as he robotically wrapped his own hooves around his aching cock, the feeling of aching becoming too much to bare, "That's pretty damned big for a stallion."

"It is, it's just over twice the size of the average stallion," Twilight looked at his impressive shaft as he subconsciously began to stroke it, the feeling of his hooves rubbing along his dampened shaft had a wondrous effect on his mind, "Rainbow Dash, you are, quite literally, twice the stallion most stallions are."

Rainbow let out a single syllable laugh as he properly appraised his fleshy totem. Then he randomly thought back to what Twilight had said when he woke up, "Wait a minute, you said there were three things you needed to do, what's next."

Twilight grinned as her eyes lowered in a sultry gaze once more. "Biological Evaluation," she purred and winked, both with her eye and with something else, "now I know how big it is, it's time to know whether it actually works or not."

Rainbow blinked, but before he could react Twilight once again climbed up on the bed.

"I need to know the extent of the difference between how you'd react as a mare and as a stallion," once she was on top of him, she turned around and sat on his chest. Her dripping pussy dampening the stallion's barrel as the aroma of arousal overtook his mind, once seated, she turned her neck to face him. "So," she said, her voice becoming breathless, she leaned forward and moved so that her dripping entrance was right near his face and nose, "what does this do to you?"

Rainbow was overcome by her arousal, his mind struggling to answer her question as his penis' mind slowly took over, "It's- It... It sort of..." he breathed in deeply, "oh buck it," he gave up on trying to explain it and instead showed her what she did to him; by grabbing her flanks and shoving his snout into her winking slit. He dragged his tongue from the bottom of her slit to the top, once, twice, thrice, like he would the most delicious ice-cream. Twilight arched her back and groaned in pleasure, her wings flared as she cried out. Rainbow licked her again, but this time, forcing his tongue as far as it could go inside her. He moaned into her pussy, to employ the same tactic she used against him previously, using the vibrations to assail her mind with pleasure.

He greedily devoured the mare on top of him, her juices leaked down his snout as he tried to slide his tongue deeper within her, trying to make her feel the greatest pleasure she had ever known and succeeding. She gasped as he pulled away to get a breath of air and blow gently on her slit, causing her clit to expose itself as she winked. He blew again, trying to reveal it once more, and once it did he dove in and sucked on it. She screamed at the sensation. Her juices splashed against Rainbow's face as she came violently. Rainbow licked at and drunk the powerfully tasting liquids, giving her tender lips gentle kisses and licks to extend the feeling of pleasure overloaded.

Her head lowered down onto his throbbing erection as she rode the waves of her orgasm. "There," he said, breathing deeply due to the exertion, "is that a good enough answer?"

"Oh yesssss," Twilight hissed and moaned, letting the crashing waves of her climax slowly subside. Rainbow was waiting for Twilight to get the clipboard again to write down her observations, but she paid it no mind. After a moment of recovery, she spoke, "N- now I need to make you ejaculate..." As her mind returned to her, she slowed her breathing and attempted to return to somewhat normal functionality, she continued, "...to see if you have that functionality". She lifted her hoof and used it to push herself up. A brief flash of light caught Rainbow's eyes as Twilight cast a spell, it removed her lab coat, and judging by the residual glow on her nether regions and lower stomach, it looked like she also put an anti-pregnancy spell on herself, she was going to let Rainbow finish inside of her. This excited him to no end.

Once she was somewhat up, she turned around, faced Rainbow Dash again, and sat down. Her sensitive flesh rested on his dick, causing her to let out an exhale. As her breath returned to her, she leaned in close to Rainbow, closed her eyes, and kissed him on the lips. Rainbow wrapped his hooves around his lover and pressed his lips against hers, kissing her deeply. Twilight leaned into the kiss, letting it be long and passionate. After a few moments Twilight felt his tongue press against her teeth for entrance, she couldn't help but oblige.

His tongue was powerful, it easily fought and won against Twilight's for exploration rights in her mouth. He let her know what she tasted like as he pushed her tongue around with his, sharing the remaining 'Twilight's flavour' on his tongue. She felt his tongue explore and move around her mouth. Eventually, his tongue pulled back, allowing her to search his mouth. She didn't know what she was finding, but she could search for it for an eternity.

She began slowly thrusting, pressing her soaking and sensitive lips against his dick, causing them both to moan into each other's mouths. The action flipped a switch, they increased the speed of their movements in each other's mouths, and doubled their ferocity. They broke for a second for a breath before diving back in for more. Twilight dragged her pussy up and down Rainbow's shaft, making it nice and lubricated.

Twilight moaned as the pleasure of rubbing herself against him got too much, she broke away from the kiss and dragged herself to the tip of his soaking cock. She pressed her lips against it, letting herself get used to the feeling of pushing such a large object inside her. Eventually she stretched her lips around the tip, and pushed down. She moaned out a quiet "Ffffuck..." as her pussy stretched further around his massive shaft. She gasped and moaned, matching the sounds Rainbow Dash made as she slid down his cock.

Twilight let out a long high pitched groan as she pushed herself down further onto Rainbow's massive spire. Pleasure radiated from deep within her as the penis pushed further and further inside her. The pure thickness of the tool was distorting the size of the cock inside her, the stretching of her vagina made her believe that she was further down than she actually was. The feeling of her lower lips landing on the bump of his medial ring made her realise that she was only half way.

She stopped at the halfway point and groaned, the feeling of ecstasy crept into her brain as she began to gyrate on his medial ring. After a moment of just subsiding, she slowly lifted herself up until just the tip of his penis was still inside of her. Then she came falling down, she took Rainbow's cock passed halfway, the ring sending Twilight into a world of pleasure as her tender lips pushed over it.

Rainbow was in heaven. Twilight's tight pussy was squeezing his dick in all the right places. He moaned in conjunction to Twilight when she speared herself on him, his penis pressed up against her inner walls. She moved to lift herself again. She slid slowly upwards, driving Rainbow mad with pleasure. He wanted to grab her by the flanks and thrust into her until their hips met, but he restrained himself. He bit his lips as Twilight's clenching vagina made its second journey to the tip of his shaft.

She raised and lowered slightly, letting her lower lips kiss Rainbow's penis a couple of times, he couldn't help but thrust slightly into her, the feeling of her pussy encasing then leaving the very tip of his shaft was driving him insane. Before long, she once more slammed down onto him. The feeling of the deep penetration was too much for Twilight, as soon as she got down as far as she could, her brain lit up with the fury of another orgasm. Her nethers clenched at Rainbow's penis, trying to milk it for his glorious substance, but it was for naught; he was yet to climax.

Twilight moaned deeply as she came down from the second orgasm Rainbow had brought her to. Her head hung tiredly, her bookworm lifestyle wasn't exactly all that well versed for endurance. She leaned forward and close to Rainbow, she gave him a kiss on the lips, which he eagerly returned.

Once she broke away from the touch, she whispered in his ears, her voice broken by bliss and panting, "I... don't know how much... longer I can last Rainbow... but I need to know if you... can ejaculate." She used up a good portion of her remaining energy to extract herself from Rainbow's cock, pleasure rained through both minds from the action.

"So... I'm going to lay down here," she said, patting the bed beside the stallion, "then you... you need to take me and finish inside, okay?"

Rainbow couldn't be more excited; he nodded in eager acceptance.

Twilight then tiredly fell down on the bed beside Rainbow. She landed with her stomach down, her head resting in between her forehooves, and her flank in the air. Rainbow got up from his place and moved behind her. He inspected Twilight for a second, her features were tired, yet her hind quarters were oh so ready. The juices from her multiple climaxes were running down her leg, as they were also dripping off his cock. Twilight looked back at the appraising stallion, she waved her tail in front of him as if to say: 'what are you waiting for?'

He grinned, and climbed up onto Twilight to mount her. He thrusted lightly, and felt his penis press against her pussy but not slide in yet. He tried again, more successful this time, putting just a few inches inside her. Twilight flicked her head back straight and arched up. He could hear her cry out from underneath him, her face was flush, her eyes tired, and her mouth was open wide with her tongue lolled out. She was panting and moaning, and sending Rainbow off the fucking deep end.

He didn't want to hurt her though, so he leaned down closer to her ears and spoke in his deep ragged voice, "If I begin to hurt you, let me know, ok?" Her ears twitched at the feeling of his breath.

Twilight couldn't be bothered to speak, so she nodded.

Rainbow took this as a signal to go ahead. He began moving slowly, thrusting gently to build up the pleasure they had before, and to let Twilight get used to his tremendous size again. Each time he thrust in, he'd go to his medial ring, then start to move back out. Twilight moaned loudly with each movement, letting Rainbow know he was doing a good job.

Then, once he believed she could take it, he drove in passed his medial ring, and slowly pushed deeper and deeper inside her. Both ponies let out a long, slow moan as the pleasure of the action began to overwhelm them. Eventually, Rainbow couldn't move any more, his size didn't permit him to bottom out completely, he had maybe three inches left, but he wasn't going to push it.

The room was still, they just basked in each other's warmth for a moment, letting the sounds of panting fill the room. Soon, Rainbow began to move once more, he kept his thrusts deep and quick inside of her. Never moving passed his ring, and never going too deep inside her. He gyrated as he did so, sliding against as much of Twilight's nerves as possible, sending an overload of pleasure into her mind. He sped up, his thrusts became more drawn out before pushing back in, letting his medial ring glide over her aching pussy.

Twilight let out a series of short gasps at his motions. It was a short while of this before Rainbow started to draw out completely before diving right back in. Causing him to moan through clenched teeth, and her to moan through open mouth. Faster, he thrust into her, sliding deep into her and pulling himself out. He was like a piston in a very well oiled machine.

Twilight screamed between pants as another orgasm wreaked havoc through her body and mind, the waves of pleasure only splashed in tandem to Rainbow's thrusts as he pushed and pulled in her with the added traction of her spasms. He sped up. He began letting out short breaths of air through his nose as he pumped in and out of Twilight with feverish pace.

He grunted out every breath, the air pushed down and slid off of Twilight's sweaty body. Her neck was bent back as much as the powerful stallion on top of her could allow, her mouth was open and she was gasping for breath. She was panting as though she was running. She knew it was only a short while ago that she came, but regardless, she could feel the pleasure amounting again. As Rainbow pumped in and out of her, she ended up losing all thought and all worry, she had no concerns aside from the gargantuan hunk of meat being shoved inside her. Her wings flared out and brushed against Rainbow's side as she gasped and moaned. Her voice reaching a crescendo of screams and pleasure.

As he charged inside of her, Rainbow could feel his testicles begin to tighten. They swung with the motion of his body, they flew up and slapped himself lightly on the part of his dick he couldn't fit inside her. The pleasure began welling deep within his stomach and hurriedly spread throughout his body. He was cresting upon the cliff to climaxing, he could feel himself tapering on the edge. With one final push inside Twilight, he jumped off the edge of the cliff and landed in a pit of ecstasy. With the sound of another strained pleasurable cry from Twilight, he knew he brought her down with him, once more pushing her into a ocean of euphoria.

The dam broke. His penis pulsed as rope after rope of his cum splashed inside Twilight. Filling her with his potent seed. His penis flexed again and again, pushing more of his cum out of it and into Twilight's womb. Eventually, the spasms slowed as he rode his own wave of pleasure down back to earth. He was spent, and by the looks of Twilight, she was completely discharged.

He slowly pulled himself out of Twilight's aching pussy, one last spike of pleasure ruptured through both of them as his penis popped out of her, letting out one more glob of cum as it twitched. His seed fell out of Twilight's entrance slowly, the liquid being far too much for her to contain. He picked up Twilight by the flanks, an action that expended more energy that he believed he had, and pushed her rear up further onto the bed, letting her tired body rest from the pounding it had received.

Rainbow wasn't fairing much better, he felt like he ran several marathons, all at once, all while carrying several tonnes of lead on his back and dick. He fell and rolled into the bed to lay next to Twilight, who had rolled over to allow him to fall in bed easier. They were both thoroughly exhausted. Once he was settled on the bed, he reached over and pulled Twilight close; leaning in by spooning her with his softening penis. He reached his head up and gingerly planted a kiss onto Twilight's cheek, causing her to smile through her tiredness.

Before they both departed into the land of dreams, Rainbow heard Twilight mutter something. It was with a breathless, tired whisper that Twilight mumbled her last words before she departed into a blissful sleep.

"Experiment... Successful..."

Rainbow laughed softly under his breath and hugged Twilight closer. She sighed from the close contact and leaned back into Rainbow's embrace. He breathed in her scent one last time before drifting off into a restful slumber.