"So was it always there or did it just pop out when you became a Princess?"
Twilight yelped, feeling a small hoof poking at her slowly-hardening length that was gradually extending down towards the floor.
"Sweetie Belle! Do you mind?"
Sweetie looked up at her, grinning.
"Nope, it's kinda cool actually! Wish I had one."
Twilight sighed. Her length was pretty much at full hardness but still growing, the wide head pressed firmly against the library floor and leaving a smear of pre as it began to make its own room, pushing forward between her forelegs. Sweetie Belle followed it with her eyes, her expression of surprise growing along with it. It wasn't long before her balls got in on the act, stretching and drooping as they expanded like balloons attached to a hose, filling up with pints of jizz and reaching down past her knees, causing her to widen her stance to give them more room which they happily used up.
"That's not what I meant, Sweetie Belle. Poking the privates of other ponies isn't the done thing. Darn, now it won't go down until I jer- uh, until I... wait for a while."
Looking down, she could see the head, now wider than her neck, sticking out between her hooves, and could feel her balls pushing firmly against the insides of her lower legs. Fuck, she needed to cum.
"Gee Twilight, you're really swelling up. Are you allergic to me?"
Twilight almost managed a laugh, but shivered as she reflexively thrust forward a little, the underside of her cock head rubbing against wood.
"And these look a little swollen, might want to get 'em checked out."
She prodded one of the now volleyball-sized testicles firmly.
"Nuh-ungh!"
Twilight choked, her words sticking in her throat as Sweetie Belle's touch caused her balls to seize up. Her three-foot length lurched, and a fat rope of cum spurted out, splattering against a shelf full of books. She hadn't quite cum, but came damn close.
"D-Dammit, Sweetie, stop that!"
Sweetie just giggled, and trotted round in front of Twilight.
"Jeez, Twi, no need to be such a prude! I heard you were but this is just silly."
Twilight blinked.
"Wha?"
"Oh yeah, Rarity's always going on about how embarrassed you get when you talk about sex n' stuff."
Twilight grit her teeth and exhaled, trying hard not to get too excited and bowl Sweetie over with a jizz upper cut from her huge flare - that was now barely a foot from the filly's face.
"Guh. I'm not embarrassed, it's just hard when you haven't had some thing like... this for very long, just takes a bit of getting used toooooo"
Sweetie had pushed her face into Twilight's slit and stuck her tongue as far down as it would go. Twilight was practically convulsing, a series of near-orgasms sending mouthfuls of spunk into Sweetie's waiting maw. She promptly withdrew her tongue, and licked her lips.
"I know you wanna cum, Twilight. Stop holding back."
Twilight sighed. Dammit, she did. She sat down, legs spread wide to make room for her balls, and steadily held her length out, its sheer weight pulling it down until it was almost horizontal.
"I can't believe a filly is the one calling the shots here. Fine, I will, but only because these are starting to get a bit too full for my liking."
She laid a hoof on each testicle, the gentle, rhythmic pulsing almost therapeutic.
"Just... Don't poke me any more, okay?"
"Alrighty!"
Sweetie sat back as well, holding the foot-across head in her hooves. She applied some pressure, eliciting a groan from Twilight who was now resting against the wall behind her.
"Heh. You really do need this, don't ya?"
"Mhmm"
Her lips made contact with the tip once more, and she ran her tongue along the slit, causing the entire length to lurch as Twilight moaned lewdly. Her balls surged, billowing upward onto the tops of her legs. She was close.
Sweetie kept licking away at the melon-sized head like an ice cream, slowly applying more pressure to it. By now Twilight's tongue was hanging out of her mouth, her chest rising and falling.
Hearing an ominous rumbling, Sweetie drew her head back, shifted to the side and wrapped her forelegs around the thick shaft just behind the head, giving one last squeeze.
With a guttural cry, Twilight let go.
Her enormous dick shuddered, then erupted, a thick, white geyser exploding outward and splattering noisily against the bookshelves fifteen feet in front of her. The pleasure was so immense that she could barely move, frozen stiff as the mind-numbing sensations washed over her, gallons of spooge spurting out and up, drenching the wall in layers of sticky, hot jism.
Sweetie Belle could only look on as Twilight continued to cry out, her enormous cum-laden balls convulsing and quivering, working as hard as they could to empty every last ounce from their seemingly bottomless depths and sending each over-sized blast of their immense load rocketing out to douse the books ahead, knocking some from the shelves and landing in the growing lake of murky white on the floor below.
Near-hyperventilating, Twilight's heart rate gradually began to slow as the last few ropes, less powerful but still many times larger than the average orgasm, sputtered out and coated the floor in front of her throbbing flare. She let her head fall back as her engorged shaft began to flag, settling against the floor with a quiet thwump.
Sweetie Belle sat down beside Twilight, patting the base of the huge purple length beside her.
"Feeling better?"
Twilight, breathless, managed a 'yep'.
"Good, 'cus we're totally doing this again some time."
Applejack squeezed her nine-foot body through the doorway, her hat knocked off her head by the top of the frame. She leaned over to pick it up, her head-sized breasts pressing against her taut abs.
Picking it up, she tossed it onto a chair in the corner and began warming up, rolling her shoulders and twisting and stretching her thickly muscled arms. Turning, she looked into the mirror running the lengths of the weights room, and noticed her she could only see herself from the neck down - that was new. She could only grin as she looked herself over.
"Heh. If this keeps up I'll be bigger'n Big Mac."
She loaded up the barbell to the weight she'd just about gotten used to and found lifting it with one arm was... not exactly easy, but certainly doable. She loved the way holding it with just one arm made all the muscles on it really pop. Fuck, she was big - and loved it.
Standing in front of the mirror with the bar at waist level, pressing lightly against the bulge at her crotch, she began to pull it upward. With an ease that surprised her, she quickly completed the first rep. Jeez, she really was getting even stronger. She got into a rhythm, steadily pulling the 150-pound payload up to squash against her sizable tits and holding it there briefly before lowering it back to her waist, her huge biceps relaxing and her triceps blossoming slightly with the straightening of her arm.
With each rep, her swollen shaft flexed and bucked ever so slightly, as if demanding release from its cloth prison. After a dozen or so reps, she could feel her yoga pants were a little tighter over her hips - she looked down between her arms and saw her waistband had been pushed back, a glimpse of her semi-hard shaft visible, stuffed into her underwear. The bulge stuck out a good six inches from her waist and was only growing, her lengthening and thickening cock snaking around and taking up more and more space as it grew and grew, soon forcing its way out of her underwear and down one leg, while her grapefruit-sized balls expanded and gurgled, filling with a good-sized load.
Applejack pressed on, though. It definitely wasn't the first time this had happened. She finished her set of fifty reps - just. Droplets of sweat were running down her forehead, not from exhaustion, but from trying not to blow a huge load in her pants. Every time she looked at herself in the mirror, she adored what she saw. She found it hard to admit to herself, but she turned herself on.
The huge barbell fell back into the holder with a resounding CLANG. Applejack reached up to wipe her brow, that simple action alone enough to cause her enormous bicep to bulge outward - she noticed this, and brought the rock-hard sphere of muscle to her lips before planting a kiss onto it. Oh, Celestia did it feel good to be this big, and she was only getting bigger.
She stepped back, her basketball-sized breasts, barely covered by her t-shirt that didn't reach her navel, bouncing erratically. She brought one huge arm up in a flex, the immense muscles growing and hardening before her. With her other arm she reached across and ran her hand across her bicep, enjoying the sheer sense of power it projected - perhaps enjoying it a little too much...
Her eyes fell downward to the fat bulge running down to her knee, making it look like she'd stuffed an over-sized salami into one leg of her yoga pants. Damn, she was making herself hard again. Here she was, only twenty minutes into her workout, and all the rubbing and caressing of the fabric against her length had already got her hot and bothered. She ran a hand along her girthy dick and shivered - it seemed to inflate even more.
"Mmf... Gah. Darnit, and here ah was thinkin' I might actually get through a whole darn workout without goin' off like a firehose. Better take care a' this before it's too late."
Stepping back out into the main gym space, she made her way to the restroom, each footfall being felt by everyone in the gym. If that didn't get a pony's attention, her towering, herculean frame sure would as she gently pushed her way through the milling groups of gym-goers.
"Sorry, everypony, got certain matters t'attend to."
Forcing herself through another doorway, she forced herself into a pokey toilet stall and just managed to pull the door in and close it. Shoulders rubbing the sides, she fumbled with her pants and underwear, managing to retrieve the runaway cock that had slipped down to her shin by this point.
She loved every part of her huge body, and her penis was no exception. She could tell it really wouldn't take much work to push herself over the edge. She took her member in both hands and began rubbing and caressing its length.
"G-gah... nn..."
And sure enough, it didn't take much work. Giving in to the overwhelming desire to climax, she firmly grasped her cock and gave a few hard pumps, which was more than enough to open the flood gates.
"Aaahnnn!"
Gritting her teeth and moaning through them, her hips bucked along with her shaft, which recoiled with the sheer force of the explosive blast of jizz that smacked against the wall above the toilet. She wrestled it downward, trying to aim for the bowl, and just managed through the fog of bliss to line up with it as the second fat gout of cum exploded from her convulsing cock. Then another, and another. A good couple of liters of hot, thick semen coating every inch of the bowl and nearly filling it.
Her spasming dick began to run out of steam, her balls clenching one last time as the last few dregs of jism oozed from the tip and fell into the bowl. Applejack just managed to stay on her feet, her massive muscles almost outmatched by the near-overwhelming pleasure of her orgasm. Shaking off the last little drops, she folded her length back into her underwear, pulling her pants back over her wide hips.
She felt a lot better, but didn't doubt she wouldn't be completely satisfied until she'd gotten off a few more times - it seemed her libido had grown along with the rest of her. As big as she was now, she was certain she wasn't done growing yet.
Rainbow Blitz was talking to the rapidly inflating slab of meat stretching down the leg of his exercise pants. It replied by fattening even more and stretching down towards his knee. Blitz could only groan and clench his fists as his cock grew ever-thicker and longer. He liked these pants, they were loose-fitting and made long, full strides very easy – when he was soft, anyway. And he usually was, but today he hadn't taken care of his morning wood, deciding that a few extra minutes down at the track would be time better spent. Less than an hour later, he was regretting that decision.
“Hngh...fffugh...”
Blitz grit his teeth as he came to a stop, leaning against a light fixture beside the track. He wasn't tired, but if he carried on the rubbing of his fat dick against his pants would make him blow his load whether he wanted to or not. So, seeing no other way to calm himself down, he gave himself a breather and hoped he'd get at least a little softer.
He looked up, watching a few other regulars jog past, too fixated on keeping a steady pace to give him little more than a glance out of the corner of their eye. Apart from one mare, a newcomer, Blitz reckoned, who slowed from a quick jog to practically walking pace as she passed by him. She kept walking absentmindedly, swinging her arms a little to keep some semblance of rhythm, but her eyes were fixated on Blitz's swollen shaft, the bulbous head resting against his knee. He glared at her, sighing noisily.
“Yeah, I've got a big dick. You got a problem with that?”
Her eyes widened, cheeks flushing a deep crimson. She seemed to be fishing for something to say, but settled with “sorry!” and bounded away.
Blitz would have laughed out loud from the lunacy of the exchange, but he was far too preoccupied with more pressing matters. Matters that were, by now, pressing against his shin.
“Shit. I gotta get out of the open before I make a real fuckin' scene.”
Blitz looked over his shoulder at the changing rooms. They were only a hundred yards or so away, but as he set off, it felt like a lot more. Initially stepping off at a slow jog, he had to slow himself down a little as even at that pace the friction was just too much.
Ugh... gotta be careful. Real careful.
He felt the weight of his overfilled balls pressing against his thighs. If they weren't so tightly packed into his clothes he was certain that they'd be swinging around and thwacking against his legs. There were stares from both genders as he shuffled along beside the track, runners drifting out of lanes as they couldn't help but stare at his monstrous erection.
By the time he'd reached the changing rooms he was waddling, his huge, swollen nuts almost down to his knees, brimming with hot, roiling seed, aching to be emptied. Thankfully the room was empty, Blitz really couldn't afford to take his time dealing with more ogling strangers. His entire length was shuddering, convulsing with need, so desperate to blast thick, fat ropes of jizz as soon as possible.
“Fuck... oh, fuck, I gotta cum so fucking bad.”
Concentrating hard on keeping his jizz inside his nuts, Blitz didn't spot the brown pegasus tucked away in a corner of the room, towelling himself off and sipping from his water bottle. He'd almost made it across to the showers (he deemed it too risky to waste time squeezing himself into the little toilet cubicles all the way down the corridor) when he heard a voice behind him.
“Aw, has little Blitzy had an accident?”
He turned, scowling, towards the voice.
“Go fuck yourself, Dumb Bell.”
Dumb Bell was about to retort, his mouth opening, but the words caught in his throat. His gaze was drawn inexorably downward towards the long, wide shaft straining against Blitz's pants. So long and wide, in fact, that it was starting to look like a third leg. The color drained from his face. He was thankful that the room wasn't well lit, otherwise he was sure that Blitz would have seen the erection tenting his own pants.
“Oh? Got nothing else to say? Cock got your tongue?”
Dumb Bell's cheeks reddened as he pushed his knees together, trying to hide his raging boner.
“Asshole.”
Blitz just rolled his eyes and turned away. Dumb Bell's eyes followed Blitz's rear out of the room, his ample bubble butt filling out his pants almost as nicely as his humongous cock did.
Blitz would never say it to his face, but Dumb Bell was pretty hot. His cutie mark was a dumb bell, and boy, didn't it show. He was ripped.
Dammit, this isn't helping.
Blitz tried to clear his mind as he staggered the last few steps to the shower room door, then almost fell through it, trying to keep his knee from bending and sending another bolt of pleasure along his throbbing length.
“Finally. Now...”
Someone less-endowed could simply pull down the waistband of their pants and have quick, easy access to their little friend. But Blitz didn't have that luxury. He bent forward, pulling his pants all the way down. As the tip of his dick cleared the waistband it sprang up, flicking pre everywhere.
As Blitz had suspected, his expanded nuts had long outgrown his underwear, digging into the soft abundance of flesh at his crotch. He pulled them off and down to his thighs, now finally having unrestricted access to all of his goods. His dick was a sight to behold, it stretched out almost two feet in front of him, angled slightly downward from its sheer weight. It throbbed and shuddered in the cool air.
Blitz wrapped both hands around it, feeling its warmth heat up his palms. Almost immediately, it throbbed harder, and half a cupful of pre oozed out of the tip, splashing against the floor.
“I know, big guy. I want this as much as you.”
Blitz didn't talk to his penis very often, but sometimes it really did feel alive in his grip. He could feel it gently pulsating, emanating warmth, responding to his touch.
He started gently double-fisting as much of the thick shaft as he could reach, the sensation was electric. Erotogenic nerve endings all along its length thrummed with pleasure, Blitz slowly massaging his member as if it were the limb of a lover.
He stuck his hand into the fountain of pre now flowing from his broad head, and lathered it along his pillar of meat. Oh, yeah – now he could start pumping.
And he did. Back and forth, faster and faster, his heart beat raising and his breathing speeding up.
“Oh yes, yeeees... mm...”
He sighed and groaned as the pleasure doubled. His dick raised a few more inches as his pace quickened. He could feel a pressure building all along its length, could feel his balls churning, waiting for the moment they could unload their contents.
“Fuck! Yes! So fucking gooood!”
He started squeezing harder, his hands milking his cock in long, hard motions. He could feel it; he was getting very close.
“Oh gods, ohh shit, here we go, fuuuck!”
Blitz cried out in ecstasy as his balls clenched hard, sending a fat blast of spooge rocketing out of his dick. The rope of thick, hot jism easily made it to the wall ten feet away and splattered noisily, the sound almost echoing around the tiled room.
“Ngh, gah!”
A second rope, even larger than the first, blasted out of his slit and coated the same spot on the wall, rolling down and pooling on the floor. Blitz could only puff and pant as his beast of a cock heaved, shooting out blast after blast of white, sticky jizz. His balls seemed able to offer a limitless supply, clenching, un-clenching, and clenching again and again, pushing out impossible quantities of spunk.
By now, Blitz was practically wailing, lost in incredible feeling of his enormous balls sending buckets of jizz up and out of his rock-hard dick, splashing, splattering, showering the wall, the blue paint disappearing beneath a coat of white being applied in liberal spurts.
Slowly but surely, the ropes weakened, and Blitz's shaft flagged. One final lurch sent a dollop of cream splurting against the tiles beneath his feet.
Basking in the afterglow, Rainbow Blitz could only feel proud as he laid eyes upon the white tapestry stretching out in front of him.
Sweetie Belle could feel each clearly-defined throb from the enormous cock draped over the front of her chair and onto the floor. Her balls, each closing in on two feet across, were just touching the floor as well, and achingly full. She could tell that she was going to blow a big load soon, whether she wanted to or not.
She could feel her length surging and fattening as it slithered along the floor, towards the pony sat in front of her.
Unaware of the turgid spear of flesh closing in on the backs of her legs, Scootaloo sat moping, moved to the front, centre seat for the umpteenth time for 'disrupting the class'. Her own sizeable dick lay draped sideways across one thigh, still oozing a little pre from the orgasm she'd brought herself to a few minutes ago, the very thing that had put her in the detention again.
All three of them were in detention together for what Ms. Cheerilee considered "inappropriate sexual behaviour".
Scootaloo argued that she couldn't help she had over-productive balls that decided to empty themselves when they wanted to, but Cheerilee was having none of it.
"I've got testicles down to my shins, Scootaloo, but when's the last time you saw me making a mess while teaching? Well, aside from a few drops of pre here and there... never! Because I manage and control it. You just have to..., deal with it before coming in to school, that's all."
The fillies knew it was true. despite her enormous balls and monstrous cock that was a good six feet long when erect, Cheerilee had never had an orgasm during class. All three admitted to themselves that they'd love to see it, though.
Sat behind Sweetie Belle, who was in turn sat behind Scootaloo, Applebloom began scheming - if they could get Cheerilee to orgasm in here, she wouldn't have a high horse to sit on, and would probably let them go home out of sheer embarrassment.
She leaned forward.
"Psst. Sweetie!"
Biting her lip as her cock continued to slither forward, forcing Scootaloo's legs apart who looked down with a start as it reached its full four-foot length and stopped beneath her desk, Sweetie Belle looked back over her shoulder.
What?
As quietly as she could, without making Cheerilee look up from her paperwork, she explained what she had in mind. Sweetie agreed it'd be a good idea (and pretty hot to see their teacher actually cum), and so she passed the message on to Scootaloo.
Since Sweetie was already pretty close to blowing a load, they decided she should get things going.
"nnn... mmm... ohhh..."
Cheerilee raised an eyebrow and looked up.
"What is it, Sweetie Belle?"
After a bit more feigned moaning and groaning (although she was pretty darn close to the edge already), she gave Cheerilee a needy look.
"Miss Cheerilee, I really need t-... to... you know..."
She encouraged her monolith of meat with a few firm rubs, drawing out a good cupful of pre which splashed against the floor in front of her tip.
At that alone, Cheerilee's cheeks reddened a little, and her heart fluttered.
"Okay, Sweetie Belle, okay. You can head outside and relieve yourself."
Sweetie groaned again as her cock flexed, stretching out another inch or two and oozing more pre.
"I... don't know if I can make it. My... balls feel really full, can you help me? Please?"
Sweetie Belle's act was apparently convincing, because Cheerilee opened a draw in her desk and took something out, then promptly stood up and trotted over to her desk, her over-sized member swinging in front of her.
"Luckily I had a spare condom. Here you go."
No sooner had Cheerilee pulled it up from the tip to Sweetie's crotch, her balls rumbled and surged, before her flare bloomed and a huge cumshot stretched out the condom, a volleyball-sized sphere of cum forming at the tip. Several similarly-sized shots followed quickly, the condom seeming to hold together well enough.
"Oh, miss, I'm feeling a little... excited, as well. I'd really appreciate a helping hoof~"
Cheerilee rolled her eyes and stood up straight.
"Why is everypony on a hair trigger today?"
Apparently including me, she thought to herself as the stirring in her crotch grew in intensity. Her large, wide flare was scant centimeters from the floor as her entire shaft continued to thicken and lengthen. The sight of these oversized dicks and sloshing ballsacks, as well as the musk, was really getting to her. She turned to see Applebloom's three-foot shaft, straight as an arrow, shuddering violently. Before she could turn around and go rummage for more condoms in her desk, Bloom erupted.
"Aaaaah!"
Applebloom wailed as her cock exploded, flare widening to accomodate for a huge spear of jizz that flew upward and easily made it to the ten foot-high ceiling, splattering loudly against it and sending a shower of white droplets over everyone. Cheerilee stepped back to avoid the growing puddle of jism around Applebloom's desk, only to hear a sucking and moaning at the front of the classroom. Sure enough, there was Scootaloo, a good third of her thirty-incher stuffed into her muzzle, her cute little face a picture of sheer bliss as she sucked herself off. It wasn't long before her own orgasm arrived, thick blasts of cum flooding into her mouth which she eagerly swallowed down, before quickly filling herself up. She pulled her maw away with a *pop*, her still-spasming shaft splattering cum all over her face and chest. The room was now a chorus of splashes, splatters, moans and groans.
This was all too much for Cheerilee. She just managed to shakily get back to her own desk, six feet of turgid cerise flesh proudly pushing out between her forelegs, balls scraping along the ground beneath her. She plopped down into her seat just in time for her balls to evacuate their load - a truly staggering volume of hot, creamy essence going from one end of the room to the other, soaking the far wall in a barrage of her seed.
Sweetie Belle was still going, and by now her condom looked like a white bean bag. She hadn't been holding the condom, and the force of each shot rolled it back over her length a few inches. One final jet spurted into it, the end slipping off of her tip and the contents washing over the floor. Combined with the three other monumental orgasms in the room, the room began to slowly flood with jizz.
After another minute of so, and a chorus of cries and moans, the fountains of cum began to peter out. A good inch-deep layer covered the floor as the four ponies sat motionless, basking in the afterglow.
It wasn't often that Princess Twilight invited her brother alone to her castle in Ponyville. But here he was, following her along corridors and up staircases to the master bedroom. He gathered from her demeanour that this meeting was likely to concern some sort of... intimate matter. The winks and lip bites she'd been throwing him were something of a hint.
Actually, thinking about it, he hoped it did. Her loose, elegant robes did little to hide the curve of her incredibly wide and fertile hips that framed an equally spectacular ass that wobbled and jiggled with every step - and standing directly behind her, he had a rather good view. Her recent ascension to alicornhood had transformed her from a cute but quite nondescript bookworm into a towering voluptuous goddess that rivalled the Princesses of the sun and moon, a head taller than her big, buff brother that once towered above her.
They reached the large door of the bedroom, Twilight producing a little silver key. She fumbled with it momentarily, and unconvincingly dropped it on the floor. She turned to Shining, her watermelon-sized tits stuffed very tightly into her dress proving incredibly hard not to sneak a glance at.
"I'm so clumsy, aren't I?"
She turned back, bent over and pushed her hips back, slamming her fat ass against Shining's crotch, drawing a suppressed grunt from his lips as she reached down for the key. She slowly straightened back up, her big butt still firmly pressed against her brother's groin, as she twisted the key in the lock. The door swung open and she stepped through it, Shining sighing in relief as the pressure against his awakening dick was released, only to be replaced by the tightness of a burgeoning erection in his underwear.
"Why don't you have a seat?"
Twilight was patting the bed next to where she was sitting.
"Thanks."
The soft mattress sunk beneath his weight as he sat down, and Twilight nestled in close, resting a hand on his thigh.
"Great to see you again, Shiny. Been way too long, hasn't it? So nice to have you all to myself."
A bead of sweat rolled down Shining's brow. He suddenly felt very warm.
Twilight followed his gaze down to her huge jugs, acres of mulberry cleavage on full display. She noticed the growing bulge at his crotch too and smirked.
"Thank you, Shining. Though I can't help feeling a little guilty. I've left my 'big' brother behind, haven't I?"
Her fingers slid a little further across his lap, mere centimetres away from his bulge.
"Wh-what do you mean?"
Twilight squeezed her brother's bulging bicep; he looked simply delectable filling out that white button-up shirt.
"I'm sure you've noticed the little growth spurt I've gone through. It's made things different between us. I loved having a big brother, and I know how I can have one again. Not that you're little now, of course - but a big mare has big needs."
Shining gulped. Twilight's hand was now resting *on* his bulge, and gripping it ever so lightly.
"Oh? What did you have in mind?"
She squeezed a little harder, her brother squirming under her handhold.
"I'm an alicorn now, Shiny. I thought my magical abilities were pretty impressive before, but now? I've got so much magic I don't know what do with it all. Well, I had an idea. And that's why we're here. Together. Alone."
Her horn glowed, and Shining felt a tickle along his spine.
"I can make you bigger, Shining. So much bigger. Enormous. The biggest, strongest, most well-endowed stud in Equestria. A limitless libido, enough muscle to lift this castle on your shoulders, plenty of energy and enough desire to keep up with little ol' me."
Shining Armour's heart felt like it was trying to burst out of his chest.
"Whaddya say?"
He looked into her eyes and nodded like a filly being offered candy.
"Great!"
Her horn gleamed with an intense light, and Shining felt a great surge within himself. He could feel something coming on. For a good ten seconds, the room was bathed in ethereal light as the alicorn poured untold amounts of magical power into his being. The light began to diminish, then receded completely. Twilight kissed him on the cheek.
"Enjoy, stud."
Shining looked down at himself. He felt a little dizzy. It was a pleasant dizziness, though. His shirt sleeves felt irritatingly tight. He gave his arms a flex and they tore open, glimpses of his white coat showing through. His legs ripped great holes through his dress pants as they piled on muscle, growing thick and corded.
Inside his underwear, things were decidedly cramped. His cock grew fatter and longer, stretching the white fabric as it elongated and widened. His balls, too, couldn't help but billow outward to greater and greater sizes. Shining felt like he was cumming perpetually as his junk grew and grew, the front of his boxer shorts being stretched out of recognition by a pumpkin-sized bulge - and still he grew.
"Oh, Celestiaauughhh--"
He groaned deep in his throat. His underwear finally snapped. A cock as big as his arm unfolded and flopped out in front of him, draping over his gurgling basketball-sized testes, before its insurmountable hardness managed to lift its great weight upward. He watched in slack-jawed wonder as it reared up like a stallion and slapped against his broad chest, sputtering pre against his neck. With a rumble and a creak, it sprouted upward, the head swinging lazily above him. He wrapped both burly arms around it and pulled it in - he never thought he'd ever have a cock big enough to hug like a pony, but here he was, locked in an embrace with his own member. He paused as his balls gave a loud burble, then cried out as they practically doubled in size in the blink of an eye.
It was time for the rest of his body to catch up to his oversized goods. His entire body began to expand in all directions - his pecs jutting out even further than they already had been, his abs even more exquisitely cut, his back broadening, his firm butt ballooning out into twin spheres of rock-hard muscle. He allowed himself to fall back onto the enormous bed he was sat on, and slowly grew across it. It was king size, but by now seemed more like a single to him.
Twilight practically threw herself onto the bed beneath him, grabbing his balls with both hands and ploughing her face into them. Shining could only writhe in ecstasy as she gave his nuts her full care and attention. By now, his legs were dangling off the end of the bed. His frame was packed with muscle and his cock was almost as tall as Twilight, standing straight up and not far from the ceiling. Twilight was thoroughly enjoying herself, face deep into his big, round balls, inhaling lungfuls of his irresistible musk. Shining had both hands on the base of his cock and was pumping hard.
"Mmm, you gonna cum for me, big guy? Don't worry, you're not gonna empty these things any time soon."
She dove back into those alabaster beanbags, encouraging her brother to spill his seed. How could Shining refuse? His toes curled and his cock bucked, he was right on the edge. It just took a big squeeze to his ballsack to send him over.
"Cuh-uhngh - aah!"
Twilight felt and heard a rumble in his balls. His flare opened wide to make way for the onslaught of jizz that climbed his monolithic member in a flash, and the first rope crashed against the ceiling, spraying them both. Another fat rope, then another, each splattering powerfully above them and drenching them in cum. Shining moaned uncontrollably as ecstasy ran through his veins, his enormous muscles flexing with each orgasmic pulse. Twilight had taken to massaging the base of her brother's tree trunk of a cock, coaxing out as much of his thick, hot spunk as she could.
The cavalcade of spurts went on and on, Shining's supply of spooge seemingly truly infinite. His sister wanted a sex machine, and by the stars she'd made him into one. By sheer force of will, he pulled himself down from the knife-edge of absolute bliss of cumming with an eight-foot cock, and the geyser of jizz started to diminish. Twilight was impressed, he could have gone on for hours with the amount of sexual energy she'd dumped into him but he'd reigned himself in pretty quickly.
Cum was everywhere. The two of them and the bed were blanketed in white, the ceiling was plastered and dripping with his essence, the floor around the bed was saturated, and his cock was still rock hard.
"That was a good warm-up, Shiny. Wanna get started?"
