The Most Satisfying Serum

“Yes, just a little more…”

Everypony else had left the lab hours ago. It was dark out, Peach Sherbet could hear the roar of rain on rattling the windows of the facility as she did her best to concentrate on her work. The mare was working on a little pet project of hers that she had been concocting for the past few months when all her fellow coworkers had left for the evening. None of them suspected a thing, she often worked well past her salaried hours so it wasn’t unusual for her to be the last pony to leave. Often she had to lock the place up.

She added another ingredient, waiting as the liquid distilled properly observing the vial with her eyes intently, allowing for the serum to settle. Whilst it was, she pulled a singular slice of peach pie out of the lab fridge which she had brought in earlier in the day. It was nicely chilled but quickly came to room temperature. She placed it near the serum which was still settling and made her way over to the large set of industrial scales that they often used for various experiments in the lab. She had to check her weight before the next step.

545 pounds.

Pudgy, for a pony of her size and stature. Neither obese nor under weight. She made a mental note and then returned to the slice of pie and her serum which had now settled nicely.

Very gently, she tipped it up and poured a singular drop into a tiny beaker. It was such a small amount it didn’t even make a noise as she carefully picked it up with her hooves. Peach then dropped the liquid onto the pie and waited for about thirty seconds. Nothing changed about the food in any way. She let it come up to room temperature a little more and then took a bite. Then she took another and another. She kept eating the pie until it vanished. It was a modest slice, nothing you’d expect any average pony not to be able to easily eat.

Blooooooorrrrrrpppppp!

Uuuuuurrrrrrppppppp!

“Oh! Excuse me!” Peach said to nopony without thinking, it was a natural reaction. She felt the serum start to work inside her body. It had to be applied to food first as she had done, but then eating the food had caused it to active within her. The noise from her stomach and the sudden belch from her lips confirmed that all those months of failure and mathematical calculations were now coming to fruition with this first test. She gripped her stomach with her hooves as she felt herself fall back onto her rump from the sudden shift she was feeling within her body. It wasn’t painful in any way, it just took her by surprise. The mare wasn’t expecting such a feeling from within herself. Quickly however she got used to it, getting back on her legs as her stomach settled.

“Urgh…”

She felt herself, there was definitely extra heft and squish on her belly. She would check her weight on the scales anyway, but what she felt told her everything she needed to know. She moved herself over to them and watched as the figure counted up.

569 pounds.

She did the mental math quickly enough. An extra 24 pounds from a single slice of pie. Perhaps she had overdone the potency of the serum, her mind weighing up the consequences for having made such a powerful mixture as best she could. In the end she decided she had spent enough late nights in the lab to warrant a little excess potency. The mare grinned, she had a whole vial of it to take home and that test was just one tiny little drop. Perhaps this would be a way to give Aurora the push she needed to finally fulfil both their desires. Peach could only hope as she grabbed the vial and stowed it away in her saddle bags to leave the lab for the evening. The rain was still pounding outside, no matter, she’d just get wet.

Aurora heard the door slam shut and what she assumed was a rather wet pony shake herself off inside the porch. Her eyes glanced up at the clock sitting just above the mantelpiece. Just gone eight in the evening. Once more she reasoned Peach had been consumed in her work so deeply she had lost track of time once more.

“Burning the midnight oil?” she asked as she saw the still rather wet Peach come into the living room and place her saddlebags down by the wall, the mare then vanished before she replied to pull a towel out of the closet to properly dry herself off. When she returned she had an answer ready.

“I suppose so, I’ve been working on something.” she said with a smile, going back to her saddlebags.

“I assumed that was the case, you’ve been late most nights for the past oh...two months now? I think I’ve actually lost count.” Aurora mused. “Are you nearly done with it?”

“Yes, actually just finished tonight.” Peach replied, pulling the vial out and holding it up with confident grin. “Voila!”

Aurora tilted her head slightly. “That’s what you’ve been working on?” she said, getting off the couch she had been sitting on to come and take a closer look. “What is it?” she asked. The mare observed the mixture through the clear vial and shut one of here eyes to peer almost cartoonishy at it.

“Well, it’s to help you, I hope.” Peach said, still holding it up as Aurora continued to get a good look at the serum.

“Help me? What are you talking about? I’m perfectly fine.” Aurora replied a little confused, she wasn’t quite getting what Peach was trying to convey.

“You remember what we talked about before? The whole gaining weight thing?”

“Yes…”

“Well you were nervous right?”

Aurora thought back to that conversation they had many months ago. It quickly came back to her, she had actually hoped that Peach had forgotten about it. It seemed the opposite had occurred and the mare had whipped up something to actually try to tackle it. Aurora figured she’d try to play it cool at first. Despite forgetting the conversation the feelings certainly hadn’t gone away. Just what had Peach whipped up in that lab of hers?

“Well yeah...we talked about this Peach.” Aurora sighed. “There’s only one way to gain vast quantities of weight. Lots and lots of food. I don’t wanna make a pig of myself! Plus imagine what other ponies might say if they saw me stuffing my face all the time. I have a job you know. In the Night Guard in case you’ve forgotten. Do you know how judgemental those ponies are? Just the other month Night Glider had a link break off her armour and the rest of the guard made fat jokes for weeks! It wasn’t even her fault, it just came off by itself!”

“Yes, I remember the conversation. I think I even giggled a little when you mentioned what happened to her.” Peach replied with a matter of fact tone. “So I’ve come up with something that can help you gain weight without making a pig of yourself. In fact, you don’t have to consume much more than a normal meal with this.” Peach said, giving the vial a little shake for Aurora to just add a little emphasis to her point. She could see the expression on Aurora’s face change more to intrigue.

“How so?”

“I can show you if you want. Don’t worry before you get all uppity and worried I tried it myself in the lab, it's perfectly safe. You go weigh yourself and I’ll get a singular slice of cake out the fridge.”

“Weight myself?” Aurora asked.

“Yes, weigh yourself. You’ll see what even the tiniest drop of this serum does to regular food once you’ve eaten a slice of cake and see how many pounds you pack on.” Peach replied, getting the cake out the fridge and cutting a slice. She just heard Aurora respond “Fine, but if this is another one of your jokes there will be hell to pay!”

“Yes, because I’d spend months late at work working on a joke.”

“I wouldn’t put it past you!” came a yell from the bathroom as Aurora used the scales and then returned a few moments later.

“Well?”

“What do you weigh?”

“H-Hey, that’s a bit of a personal question isn’t it!” the flustered bat pony replied.

“It’s for science.”

“Fine. 436 pounds. Happy?”

“Yes. You’ll have a little catching up to do though. I weigh more than that.” Peach replied. “Now come observe.”

“Alright…”

Aurora joined Peach at the countertop she had put the slice of cake on. “I hope you’re not going to ruin a perfectly good slice of cheesecake.” she quipped, watching as Peach set the vial down and pulled a pipette out from one of the drawers in the counter.

“Now why on Equestria would I do that? Who wants to ruin good food?” came the rather curt reply to the query. Aurora watched as Peach used the pipette to suck up a singular drop of the serum, then turned her attention to the slice of cake and very carefully squeezing the end so that with a soundless drop the mixture fell onto the cake.

“Well that was disappointing. I really thought something amazing was going to happen there.” Aurora said frowning.

“Science isn’t always explosions Aurora.” Peach replied. “Now then, eat it.”

“Okay, but only because I’m trusting you on this one.”

Aurora was a slightly slower eater than Peach, but in a few minutes the cake was gone. When she ate the final bite, Aurora turned her head to Peach. “Well...is something...ooohhhhh….”

She felt the same sensation that Peach had felt when she had tried the serum back in the lab. Again it was not unpleasant but she count certainly feel something churning in her stomach.

Glooooorrrrrrppppp!

“O-Oh my…” Aurora blushed. “W-What was in that stuff!?” she asked, gripping her belly as Peach had to feel it as best she could. As she did so, she physically felt her body shift downward just a little. When it was all over she managed to gather herself together and unlike Peach had stayed on her hooves through the experience.

“Just a little brew I put together, now go weigh yourself.”

Wordlessly the mare left the room, Peach giving it a moment or two before she asked. “Well!?” yelling so that Aurora could hear her.

“463 pounds! What the heck!?” came the shocked response once the scales had given their final reading, Aurora came almost bounding back into the room. “T-That’s amazing! How did one piece of cake make me gain nearly 30 pounds!?” the mare asked confused.

“It’s a prototype, but once the food hits your stomach it turns it into pure fat. You can imagine how your body reacts to that. The stomach noise it made wasn’t unjustified.” Peach giggled. “That was my idea. With a little of this stuff on every meal you’ll be as big as you want in no time and nopony will suspect a thing because it will always look like you’re just eating the same as you always do.” Peach explained.

“But I’ll get fat. Ponies will say things!” Aurora replied.

“Well yes, but they’re not going to know why. Besides you just didn’t want to eat vast quantities of food right? So this is the perfect solution. Now imagine eating a whole cake with more than just a singular drop of it applied…” Peach teased a little, giving Aurora’s belly a little pat. “And we can do it all in the privacy of our own home, or heck even out if you want to. C’mon I know you want this, you know I want this. Why not just let yourself go.”

It took less than a second for Aurora to make her decision. “Fine, but it's gotta be discreet okay?”

“That’s what the serum is for! You’re gonna love it!” Peach said with a smile.

“Attention!”

It had been a few weeks since Aurora had given into her temptations with the serum. She had been eating regular meals and apart from her obviously growing body nopony had actually made any comments about her eating. She had in fact actually overheard a few confused colleagues wondering what was happening to her. “I don’t get it...she’s not eating any different in the mess. How is she so big!?”

Right now she was just starting work for the evening and duties were being handed out. Try as Aurora might she was struggling a little with her armour. Her size had roughly doubled. Before she had left for the day she had checked the scales at home which were starting to verge on displaying their maximum weight. The mare was well over 900 pounds at this point and it had only been a few weeks. Her armour, only built for a pony of smaller stature was practically bursting at the seams. At least it would be if it had seams. The plates were audibly bucking under the pressure of her huge stomach pushing against them. The mare was careful with any movement, she feared that even the slightest badly timed jolt would cause it all to come peeling off her body like a banana skin.

“Private Aurora, be on standby for any medical issues.” she heard the Captain say. That was always her duty. The mare very rarely actually saw action but she had to be on standby. Foolishly, the mare saluted a little too quickly, one of her armour plates popping off as she replied “Yes sir!” with a dutiful blush. Next to her Night Glider shifted a little uneasily but nopony said anything. The rest of the duties were distributed and they were dismissed, Aurora sighing as she un-stiffened her frame from being at a military stance and relaxed.

“Having trouble there medic?” Night Glider teased. “What are you eating recently? You look like you’re about to pop out your armour.”

“Nothing different to usual. Before you vanish off on your patrols can you give me a hoof?” Aurora asked. “I gotta get that plate back on.”

“No problem fatty.” the bat pony teased, picking it up and trying to push it back into place. “Jeez...how much do you weigh? I can’t actually line up the connection points because they look like they’ve been warped. This armour is made of metal you know…” Night Glider said as she tried to push that plate back into its rightful place on Aurora’s body. “I mean how fat you gotta be that your stomach can bend metal!?”

“I-I’m not that big..” was all Aurora could reply. After a few minutes of trying however Night Glider gave up, nothing she could do was going to get that plate back into place.

“You need to see the blacksmith for this one. Probably to let your armour out. And not that big? How long before those wings on your back become useless hmmmm?” the mare continued to tease. “Anyway. I gotta get on patrol. Have fun explaining this one fatso.” she said, taking off, passing the plate to Aurora as she did so leaving her alone in the courtyard. Aurora just sighed. She made a mental note to visit the blacksmith later. For now she had her duties to attend to.

“Well that was a farce!” Aurora angrily bellowed as she practically stomped into the house and slammed the door behind her. It was morning once more. Owing to her late working schedule and Peach’s regular one they often met in the morning as Aurora came home and Peach was heading off to the lab. The mare pulled her armour off and threw it on the floor, letting her huge body free from its metal constraints. She looked up, glaring at Peach who was sitting on the sofa eating a bowl of cereal which she put down. She thought it better to approach Aurora to try to calm her temper as much as she could.

“Now now, what’s wrong?” Peach asked.

“That serum! I knew eventually it was going to be an issue! I literally had a METAL PLATE of my armour pop off during roll call!” Aurora yelled. “Then Night Glider, you know the one I told you about? Came out with all these fat jokes! It was like she was getting back at me for all those weeks ago and I didn’t even say anything then!” the mare fumed. “She couldn’t even get the plate back in place. I had to go see the blacksmith to get it fixed!”

“Well, you didn’t think not gaining size and weight would be a side effect of this would you? You had to assume eventually you’d be so big this sort of thing would happen.” Peach said, getting a little closer to Aurora. “Besides, I think you’re starting to look rather good with all that padding.” she cooed. Peach knew a little teasing would get Aurora to calm down, plus it did give those rosy red cheeks of hers just a little more blush.

“W-Well yes, but that was embarrassing. I don’t know how much more I can keep gaining if ponies are going to start taking note. Plus the blacksmith can’t keep letting my armour out forever. Metal only has so much give…”

“So why don’t you quit?”

“What? Quit? But we need the money don’t we?” Aurora asked perplexed.

“Once again you, unlike me, haven’t run the numbers have you? I know our finances. I make enough on my own that you technically don’t need a job. Just think, you can stay at home all day, eating as much as you like, getting bigger and bigger…” Peach continued to coo. “I bet you’d like to be so big your stomach grounds you hmmm? A nice big soft bed?”

“M-Maybe...you think I could?” Aurora blushed.

“Let’s talk about it when I’m home. For now you should get some sleep. You’ve had a busy day.” Peach replied. “Besides I need to head to the lab. I’ll be home normal time.”

Before Peach had left the house, Aurora’s head hit the pillow and she was sleeping soundly.

When Peach returned that night she found Aurora in her usual sofa-bound spot. She had noticed since the mare had started putting on all that extra weight it was forming a nice groove on her side. One of the many side effects of being so heavy.

“Hey.”

“Hey, good day?” Aurora asked.

“No worse or better than most days.” Peach replied. “What about you?”

“Well I sent a letter to my Captain saying I quit. No response yet but I have a feeling he might have suspected it was coming even if I didn’t.” Aurora said. “So I suppose you get your wish.”

“My wish? Oh I think it’s your wish too.” Peach said, putting her things down and immediately making for the fridge. She pulled out a number of desserts and coated each one in an appropriate amount of the serum. There was a lot of food, she did a little mental maths and guessed that this little lot would make Aurora gain more than a few hundred pounds in one go - that is assuming she ate it all…

“M-Maybe, look I’m just not sure…” the bat pony started to say, but stopped when she saw Peach come around grinning lustily and holding a huge amount of food in each hoof which she placed on the table in front of the sofa. Aurora’s eyes went wide. “A-All that?”

“All that.” Peach teased. “C’mon, this should be easy for a pony of your size. A meagre faire of food if anything.”

“B-But...the serum…”

“Mmmmm...it’ll make it so much better…” Peach cooed as she pulled out a large slice of chocolate cake, pushing it between Aurora’s lips who just tried to protest at first, but she quickly settled into a rather satisfied series of low moans as Peach fed her all the delicious treats.

Gloooorrrrrrrpppp!
Blooorrrrrrrppppp!

“UUUURRRRRRPPPPPPPPPPPP!” It was impossible for Aurora to avoid an extremely loud and violent belch that sent ripples through the air. All this did was make Peach giggle in response.

“What a fatty, I bet you want more hmmm, fat bat?” more teasing came with more food. Between mouthfuls that Peach seemed to be feeding her at an incredible rate she did try to protest but was failing miserably.

“B-But I’m so huge already…!”

“Well nothing wrong with being a little huger cutie, plus I think that huge belly suits you.” Peach simply replied, pushing yet another dessert between Aurora’s lips.

“T-This is too big…!”

“More like not big enough. You can still move.” Peach cooed. The mare was enjoying feeding her friend just as much as Aurora was enjoying eating it. Every little piece of food she managed to get between those lips of Aurora added more and more pounds to her already generous frame. She was so obese, so big and soft… It was giving Peach thoughts that she rarely shied away from. All she wanted was to turn Aurora into the biggest and softest mare she could get her hooves on. Despite her protests, she knew it was what she wanted too.

She continued to feed her until all the food was gone, the loudest noise that Aurora made was not her protests but in fact came from her stomach as it did its best to deal with the serum enhanced food that kept filling it fatter and fatter.

Gurrrrrggggglleeee!
Gloooorrrrrppppp!

That and a few more belches in between before she finished told Peach everything she needed to know. “I think that’s enough for tonight fatso, must have put an extra 300 pounds on that blorpy body of yours.” she giggled, giving Aurora’s stomach a pat and leaning herself into it a little. The mare would do her best to hold back but she knew when her friend was big enough, she’d take full advantage of that massive belly she was putting on.

“S-So full…” was all Aurora managed to say, stumbling over her words, still rather dazed from the short but sweet stuffing session.

“I’m heading to bed fatty, I’ll see your cute self in the morning.” she teased once more, giving Aurora’s stomach a little slap as she turned to leave.

“Ooohhhhhhh…” was the only noise that came from Aurora, too stuffed to even speak much. Peach left her to enjoy the sensation. She had a few more plans for her yet.

It had been a few more weeks. Aurora was slowly adjusting her sleep schedule since leaving her job. Now waking up more in line with Peach it meant the two had more time for feeding sessions each night which Peach had been taking full advantage of and despite protests during the first few Aurora had slowly started to accept her growing figure. Besides the teasing was rather lovely, as well as the feeling she felt as her body was growing. With all the feeding sessions she was now well into the four figure mark for her weight. Probably coming up on 2000 pounds easily. Her whole body had started to compensate for the added weight, not just her belly. Her hooves had become rather flabby, small rolls of fat forming on upper regions of her chunky legs. Stomach folds were starting to appear. The mare still retained a mostly round shape that was rather pleasing. She’d be immobile if it were not for the fact her flank had ballooned in size letting her rear legs still make contact with the floor.

The mare rolled out of bed, the frame of it creaking in relief that it no longer had to support such a gigantic mare. At least until the next night. Aurora at this stage was mostly too big for much of her usual forms of clothing. Not that it mattered, she didn’t leave the house and even then it would be perfectly acceptable to go naked. But she liked to wear something to keep a little warm and well, look a bit more alluring for Peach. Socks and panties seemed to be a firm favourite. What was that comment Peach had made? Oh yes. “You know those make you look even softer…”

She had a nice multicoloured pair, but even at size XXXL they were starting to get stretched quite badly. She pulled them out of the closet and started with the socks. It was rather a struggle, the huge pony jiggling profusely as she leaned around herself to pull them up and over her hooves and onto her legs. She tried to get them on as high as possibly could but her body fought against her efforts. She felt the cloth material streeetttttccchhhh as she pulled it up. She was a little unsure if she’d get them on again without her blubber ripping through it.

Next was the panties. These met the bottom of her rear rather easily, but once more she felt the material stretch as she pulled the pair up and over her bulbous cheeks which wobbled in protest at being constrained so until the material passed over them. When she did get them in their rightful position they quickly vanished in her rear, almost giving her a wedgie due to her ass being so huge. The mare made a mental note to ask Peach to get her a larger pair. When she waddled out of the room, her sides gently brushing the door frame, she saw Peach sitting on the sofa.

“I thought you were meant to be at work?” she asked.

“I got the day off. I thought we could have a little fun.” Peach said. The mare giving her a little wink. “There’s about one third of the serum left. Wanna finish it off?”

“F-Finish it off? But I’ll be eating all day!”

“That’s the point blubber butt.” Peach replied with a rather sultry tone to her voice. “We’ve both been waiting for this, don’t try to deny it.”

“W-What were you thinking?” Aurora asked, looking towards the fridge.

“You just make yourself comfortably. I’ve got plenty of treats for such a glutton.” she cooed, going to work in their kitchen. Aurora watched as Peach pulled out a number of pastries, pies, cookies and more things coated in sugar than her greedy eyes could keep track of. Eventually the counter was covered in almost every bit of food they had not only in their fridge but in store cupboards as well. Aurora couldn’t help but drool a little in anticipation as Peach made her way around each item with the pipette and gave it the required coating. When she got to the last thing, a rather large black forest gateau she looked at the vial. There was still a generous amount of liquid left inside.

“Hmmmmm…”

“Hmmmmm?” Aurora mimicked the perplexion back. “What are you gonna do? Save it?”

“Why save it? This one can be an extra special treat.” she giggled, chucking the pipette away and dousing the cake in everything left from the vial.

“B-But, that’s so much! One bite of a single slice will add…”

“Hundreds of pounds? I know. But you’ve got to get through all of this first.” Peach continued to coo, picking up a few pastries and trotting her way over to the very nearly immobile Aurora and pushing one into her maw before she could finish her sentence. “You’re going to be so huge, the biggest and softest mare in all of Equestria.” she teased, seeing if Aurora gave any more protest style responses. There was none, the mare settled into a rather sedate chewing, Peach only hearing little moans of pleasure from her lips.

“That’s a good girl, you’ll eat everything Peach has to offer hmmm?” she asked, not really expecting a response. Aurora just opened her mouth in anticipation of yet another serum coated treat that she ate with a few mighty chews. She was certainly easing her way into eating that was for sure. Her stomach seemed to agree with Peach’s thoughts.

Blooooorrrrrrppppppp!

“Oh my, seems your body is already becoming accustomed to being so huge. That lovely stomach noise tells me you’re really enjoying this.” Peach continued to coo. She was feeding Aurora as fast as the greedy mare could eat but she couldn’t help herself. She was absolutely in love with that huge body of Aurora’s.

In between feeding her the treats she had prepared, Peach took a little time to pay attention to all the lovely softness of Aurora that she could. As she pushed yet another slice of cake into her maw she reached down and pressed one of her hooves into Aurora’s belly which only protested with a little glorp! as her hoof sunk into it deep. There was so much soft fat, it rapidly formed an almost encasing layer of blubber around her hoof. So warm and delicate but heavy and squishy at the same time. What a body, if she could get her big enough Peach thought she’d take great delight in simply sinking into it herself. But for now, a hoof and a little toying would do just fine.

“Each up fatty, I’ve got plenty to go. Don’t forget about that gateau either.” Peach said, grabbing some cookies now which she stuffed into the mouth of Aurora. It wasn’t just one cookie, it was multiple cookies. So many that she watched as Aurora’s already fattened cheeks bulged out even further almost like a chipmunk. She gave her a little time to chew on these whilst she went back to enjoying that gut down below, kneading and gripping it tightly. She was getting lost almost in her enjoyment of her massive friend as she stretched her hooves wide and tried her best to get some sort of hug on her using her blubbery belly to her advantage. It was right in the middle of a loving squeeze that she heard an indicator from above that Aurora wanted more.

“BWWWAAAAARRRRRPPPPPPPPPP!!!”

Peach pulled herself out of the jelly belly and grabbed more cake. What had once covered the counter top was now vanishing rather rapidly. Perhaps she had estimated Aurora’s eating ability. No matter, should she still be hungry she had one more little trick. It would require getting Aurora to the lab though. It might be best to save the gateau as a little carrot on a stick as it were…

“Is the big mare still hunnnggrrryyyyy?” Peach cooed. With food now back filling her cheeks she watched only as Aurora vaguely nodded in a food coma induced state of lust that rendered her speechless. The little nod of approval and more stomach noises was more than enough to tell Peach that Aurora wanted to finish off everything in front of her.

Gurrrrrrggggggllllleeee!
Glooooooorrrrrrrrpppp!

Peach didn’t even have to tease anymore, Aurora was in such a state of lusty consumption that Peach just fed her every time she ran out of food, usually easy to tell as she’d belch loudly each time her body got a chance to process the pure lard the food was turning into inside her now belly bed stomach. It wasn’t long before what seemed like a mountain of food just moments ago had completely vanished, with only that completely serum coated black forest gateau remaining.

“You want this don’t you?” Peach asked.

“M-Mmmhhhhh…” Aurora replied, still reeling from the feeding session. She must have put on 300 pounds at least or more, pushing her well over 2000.

“Well you’re going to have to work a little for it, I have one more little feeding surprise for you, but it means getting to the lab…” Peach explained.

“T-The lab? B-But aren’t other ponies working there?” Aurora asked.

“Not today, I had it closed, not just for me. I gave them all a day off. I’ve been working on something else.” she giggled. “You’ll just have to waddle your fat self there to enjoy it. I know you’re still just about mobile.”

“I-I guess…” Aurora said. “B-Better be good… Ohhhhhh, it’s so much effort to even move...I’m so huge…”

“Trust me. You’ll love it.” Peach cooed, putting the cake on her back and walking in front of Aurora. “Follow me.”

It took a while to reach the lab, mostly because Aurora was so slow to move. She tired quickly and had to take several rest breaks on the trip there. It was a little adorable to Peach to watch her tongue loll out as she panted with every step. Or was she just displaying that she was still hungry? Either way they made it. I was good that the lab had a large service door for deliveries. It was the only way Aurora was going to get in without causing any damage. It had been a little amusing to Peach when they had left the house Aurora was now so massive she had ripped the door frame clean off the front of the house as her huge bulky stomach had wedged against it. They’d get it fixed later. Might have to widen it at the same time…

“We’re here!” Peach exclaimed.

“A-At last...whew. That was a real chore to get here you know.” Aurora said, positioning herself right in the middle of the lab where there was the most room. She definitely needed it.

“Mmmm, now I’ve just got to fetch something. In the meantime, open wide…” Peach teased. “You deserve a big treat after walking soooooo far to get here.”

The gateau wasn’t given to Aurora in nice, easily chewable slices. Peach figured she’d really treat the mare, pushing the entire soft calorie and serum laden cake in her maw in one go. Aurora’s cheeks puffed out as she made a little “Mfffff!” as a protest, but once more quickly devolved into chewing as she did her best to swallow it down. Peach vanished to get the final piece to the puzzle that Aurora was keen to see. In the meantime, her body was just starting to process all that serum…

BLOOOOOOOORRRRRPPPPPPP!
GLOOOOOOOOORRRRPPPP!

It was the same stomach noises as before, but they were so much louder and more intense. Aurora actually felt her stomach rumble beneath her as she looked down and saw new layers forming right before her eyes. The cake was adding hundreds of pounds to her already ample frame on its own. She blushed and belched, her huge body feeling the exquisite ecstasy of having so much fat added so fast. She felt her stomach below her squish tightly to her legs, now so large her fattened belly pushed her rear legs and bulbous ass up high enough that she was no longer making contact with the ground. Aurora was now so huge she had hit that magical weight that granted the wonderful phenomenon of immobility. She still had her wings sure, but they didn’t have nearly enough lift power to pull such a lardy mare even an inch from the floor. She wasn’t going anywhere.

“My my, that cake really was something. Your starting to get so large Aurora. But I still have one more little gift to give and this means I can enjoy you growing as well.” Peach giggled. Aurora noticed that the mare had returned trailing a hose behind her with a few little straps at the end of the nozzle. As she looked to where the hose went, she saw it was connected to one extremely large unlabelled tank.

“I told the rest of the team I work with it was full of hydrogen. It’s actually full to the brim with melted ice cream, perfectly soft and liquidy for you. I hope you like strawberry.”

“L-Love strawberry. How big will I get?” Aurora asked.

“We’ll just have to find out, now open wide.” Peach said, pushing the hose between Aurora’s lips and placing the strap behind her head so that it would stay firmly in her mouth. Peach pressed a button on a small controller which she then placed on a counter top. Aurora watched the hose go from being slightly limp to rather stiff as the insides of it filled with the melted ice cream which quickly made its way to her mouth.

“Mffff!”

It was the last protest Aurora would make. At first it felt like she was being pumped full of the liquid at a rate she wasn’t going to become accustomed to, but it was so smooth it didn’t take her long to get used to it. It was almost like drinking really with the hose acting like a huge bloated straw. The mare once more fell into a rather lovely almost coma like state as she let her body be filled with the ice cream. It wasn’t coated with that serum, but the sheer quantity of it was more than enough to have an even more fattening effect on her. She couldn’t even belch with her mouth filled with the hose. Every time her body wanted to the gas was simply pushed back down by a lack of a route to escape from. This had the effect of her ballooning up even more, Aurora gaining hundreds of pounds every minute as she took everything that was in the tank.

Peach finally had some time to enjoy that growing body more. Now free of the duty of feeding, she could fully enjoy and experience such a bloated glutton. The most obvious place was to start with that lovely round belly.

Peach stretched her hooves as wide as she could. Even if there were ten or more of her she’d never even get close to being able to make both ends meet. It just served as a testament to the size of Aurora, who was still growing all the time. As she sunk herself in and let her hooves almost be swallowed by layers of blubber she could constantly feel Aurora’s body shifting despite the fact the mare wasn’t moving herself. It was as if every moment with the increased weight she was gaining her body was just searching out more places to expand out into. Peach was enjoying it so much that she pushed her body a little higher, now able to completely be engulfed by the biggest bat pony belly in all of Equestria. Her whole body was being covered by a large, soft and incredibly warm squishy belly even though Aurora was being filled with ice cream. It was melted after all.

But there was so much more to enjoy with Aurora growing as she was. The tank now half empty she was starting to fill the room nicely. Peach decided to scale the flabby mounts of her stomach to get to her head to give her a little more teasing. As she did so her hooves sunk in, like quick sand trying to pull a victim down except it was blubber just naturally shifting in response to the weight of Peach against it.

Once she scaled her way to the top of Aurora’s now immobile body she blushed, noting that the mare was now so large and fat a small amount of blubber was forming a tyre like layer of fat around her head which was beginning to sink into it. Even her hooves were almost nowhere to be seen, Aurora having gained so much weight that they were starting to sink into her rotund immobile frame. Any movement was out of the question. Well. Any movement that didn’t involve gentle jiggles and wobbles which Aurora just seemed to be doing in response to the pressing of Peach down upon her.

“Enjoying this are you? I don’t think fatso even does justice as a way to describe you anymore.” Peach teased, letting herself sink a little into Aurora’s stomach as she took her final position just in front of her head. “You’re gargantuan.”

“Mmmmmm...”

“Colossal.”

“Mmffffff...”

“Mammoth…”

She could have used words to describe Aurora all day, but instead she decided to carry on the teasing with actions rather than words.

“So big that I can do things like this.” Peach cooed, gripping huge hooffulls of her stomach and stretching out wide to sink her body into Aurora. Even though Aurora was so massive there was something she could do to make it even better for Peach as a thank you. The mare with a lot of effort reached her flabby almost sunken hooves out and squeezed her belly around Peach, washing her over with layers of flab and almost burying the mare inside herself.

“Ooohhhhh Aurora, that feels amazing…”

It was as before, being covered in an incredibly warm and soft layer of blubber. But with Aurora actively squishing and squeezing her own body against her, it felt even better. Blubber was permeating areas that Peach wasn’t quite able to have it touch with just sinking in. She felt her body being pressed down as Aurora was now toying with her. The feeling was indescribable. For the first time, Peach actually moaned out in delight rather than Aurora.

“Ooohhhhhhhh. More of that please.” was all she said, feeling as Aurora obliged and rolled that belly of hers more over Peach. With the tank nearly emptied. Peach simply relaxed and let Aurora have her fun, feeling the blubber wash over her as Aurora continued to suck down what was left of that melted ice cream. It wouldn’t take her long and Peach was more than satisfied she had given Aurora exactly what she wanted. The pleasing squishing and squeezes against her body told her she was more than just enjoying it. The two mares playing off each other continued to have fun even when the tank had run dry. It was a good thing the lab had a fridge packed with food. It was also just as well Peach had thought ahead and put together a number of extra batches of the serum. The fun was only just beginning...