An Experiment In Gluttony

by 555randomness

Rating: mature
Tags: Twilight Sparkle, Main 6, Slice of Life, My Little Pony: Friendship is Magic, Alternate Universe, Rainbow Dash, Random
Length: 19140

Twilight needs to perfect a previously un-mastered spell for an upcoming magic expo, and picks Rainbow Dash as her unknowing test subject. However, the "harmless experiment" quickly gets out of hoof...

Twilight needs to perfect a previously un-mastered spell for an upcoming magic expo, and picks Rainbow Dash as her unknowing test subject. However, the "harmless experiment" quickly gets out of hoof...

Contains: Weight gain and a pony unknowingly being fattened up through magical trickery.

Cover art was made by Graphene.(Formerly known as RDisbestchub)

Published 2015-06-23 04:00:02 UTC
Last updated 2018-02-16 21:11:20 UTC

The Experiment Begins

Twilight became more and more frustrated as she turned through the pages of one of the old spellbooks she had dug up. She needed to find an new spell for the upcoming magic expo but so far her search was to no avail. According to this years rules it needed to be something that was both unmastered by modern unicorns and took place over a period of time, each contestant being required to log the effects of the spell as it went on. There was an additional rule that if a live pony was involved in the experiment they couldn't be harmed.

For the life of her she couldn't find anything new though! She let out a grunt of frustration and swatted the spellbook to the floor. A few silent moments were spent with her head on the desk before she levitated the book back up to her, she was about to close it when a few particular spells on the current page caught her attention. Lined up in a column were spells about slowing a pony's metabolism, increasing appetite, and converting the current content of a pony's stomach into fat to be stored later thus emptying their belly for further eating. It didn't take long for her to figure out that these were weight gain spells.

This definitely fell into the category of what she was looking for, and it seemed like a relatively harmless experiment. It would require an actual pony subject though. Twilight initially thought of using herself, she was close to normal weight with maybe a few pounds over, but the experiment would be much better if she started with somepony who was especially small or thin. Who did she know that would work fell this? Rainbow Dash! The athletic Pegasus was the lightest of all of Twilight's friends, and the final results of these spells would have a greater contrast on her than any other subject Twilight could get.

She shook her head, was she really considering using one of her best friends as a guinea pig for this? She knew that Dash probably wouldn't take well to the idea of being fat, and Twilight knew there were several things wrong with secretly fattening a pony. On the other hoof though, it was only a temporary experiment. She was sure that she could find a spell to reverse whatever weight Dash gained when it was over. Plus, it wasn't like it would hurt Rainbow or anything. Dash's next competition wasn't for a few months, Twilight was sure she could wrap this whole thing up before her friend's life was really affected in any way.

"Twilight, you almost ready to go?" Spike's voice called from downstairs, breaking Twilight's thoughts.

"Be there in a minute, Spike!"

She couldn't believe she almost forgot about Pinkie's party that was happening tonight. All her friends would be there. It would be the perfect chance to give these new spells of hers a trial run. She could decide afterwards if she wanted to continue with the experiment or not. She tore the appropriate page out of her spell book and hid it in a saddle-bag she was taking with her before heading out.

As typical of a Pinkie party, it didn't take long for things to get into full swing. Rarity was on the opposite side of Sugarcube corner, trying to convince Fluttershy to try her latest dress designs. Spike as expected was very nearby, hoping to grab Rarity's attention whenever he got the chance. Pinkie was bouncing back and forth between different parts of the room making sure everypony was having fun. Meanwhile, Rainbow Dash and Applejack were getting into one of their arguments over who-knows-what.

Normally Twilight wouldn't pay much attention to the squabbles between AJ and Rainbow, but her interest was caught when their arguing turned into talk of a food competition. The perfect opportunity!

"I'm tellin' ya Rainbow, ya can't beat a country pony in a pie eating contest. It just can't be done," boasted Applejack.

"Oh yeah? Well there's a first time for everything. Bring it on, unless you're scared," replied the rainbow haired Pegasus.

"Alrighty then, ya asked for it. Pinkie, bring us the pies!"

Before long Rainbow Dash and Applejack were seated at a table, with a mountain of pies in between the two of them. Both mares had a look of sheer determination, eagerly awaiting the start of the contest as Pinkie began a count of three. All the others had gathered close around the table to watch the upcoming contest. Twilight had taken up a strategic position in the back, where she could see what was happening and put her plan in motion without being caught. She took a final look at the spell page she brought with her before charging her horn and casting two precise spells on Rainbow Dash to prepare her for the contest. One to spike Rainbow's appetite, making sure she'd consume plenty high calorie pies. The second was to slow her metabolism and make sure most of said calories would be converted to fat.

As Pinkie's count hit zero both competitors grabbed the nearest pie and began eating like animals. The first pies quickly disappeared, followed by the second ones, and the third. The delicious flavor of the pies only encouraged the two competitive friends to keep going. Flavors of apple,blueberry,pumpkin, and more ensured that the ponies consuming them would be pushed forward if for no other reason than to keep indulging in the amazing tastes.

However, sheer determination and great flavors could only work for so long. Around the fourth set of pies both Rainbow Dash and Applejack were beginning to slow down. Neither showed signs of giving up all together though. Twilight was keeping a special eye on Dash's belly. Before the contest began it was completely flat, but as the competition went on it was beginning to bulge slightly and become more taut as she stuffed herself beyond usual capacity. Twilight had to suppress a grin as she pulled her third spell out of reserve. In a matter of seconds Dash's belly returned to it's original state, and she now had the entire space of her stomach to fill up again. All the food that was occupying it was now gone, at-least until later when it would undoubtedly appear on her figure instead.

The effects of Twilight's spell gave Rainbow a second wind, and she soon began to surpass Applejack in sheer number of pies eaten. Although, while Applejack was slowing down more and more as things continued, Rainbow seemed unfazed and continued eating at a rapid pace. The cyan Pegasus' gluttonous zeal shocked everypony in the room, save for Twilight. The contest drew on longer than any member of the group expected, but at last it came to an end as Applejack dropped her latest pie and declared defeat.

"I'm done ya'll. Congrats Rainbow, ah don't know how ya did it...." Applejack's words were mixed in with groans, and it wasn't hard to see why. She was extremely bloated, with her belly poking out large and round from the excessive amount of food stuffed in it. Twilight was tempted to help her poor friend using one of her nifty new spells, but decided it was best to stick with one test subject for now.

Rainbow Dash wasted no time in celebrating, letting out a victorious shout before responding, "I knew I could win. That was pretty fun though, we should have a rematch sometime"

Applejack shook her head, "Maybe sometime down the road, but ah don't even want to think about any kind of food right now. I think I'm just gonna lay back and rest some of this off"

Dash shrugged in response, "Suit yourself, I'm going to keep on partying," with that Dash made her way over to a nearby table and grabbed up a piece of chocolate fudge cake. She quickly scarfed the delicious morsel down with greed. Rarity made her way over to the table and gave Rainbow an incredulous look.

"Dahling, how can you still be hungry after that contest?"

"I don't know, I had some pretty heavy work-outs today. Those can really make you work up a huge appetite. Don't worry about it."

As the party continued onward Twilight made sure to mingle regularly with all her friends. Meanwhile, whenever an opportunity presented itself she'd cast the appropriate spell on Rainbow Dash to make sure she'd keep consuming all that fatty food which had been laid out for tonight. It wasn't until things started settling down that Twilight decided to give her Pegasus friend a break, and allowed her to finally feel a full and content stomach for the first time since the evening started. Most of the group was too tired or stuffed to feel like going home, so they unanimously decided to stay the night at Sugarcube Corner. Sleeping bags were laid out and everypony laid down for the rest of the night.

Twilight happened to find herself sleeping not far from Rainbow Dash, and when her friend wasn't looking she took a long stare at Dash and tried to ingrain a mental image of her current figure to compare with her appearance down the road. It was certain to change sooner rather than later, and considering that Dash had consumed days worth of food in one night it was likely that Twilight would have some early results by the very next morning.

Author's Note

I originally started posting this fanfic on DeviantArt, but decided to expand here as well. Constructive comments are welcome.

Sabotage

It was mid-morning before the six ponies plus one dragon awoke from their slumber. Rarity,Fluttershy,and Applejack soon departed to take care of their own affairs, while Spike returned to the library to do some chores assigned to him by Twilight. Rainbow Dash was the last to wake up, which gave Twilight some time to study her body and look for any early effects of the experiment. Sure enough there was. At first glance Rainbow looked the same, but closer inspection revealed that her body was now covered in a small,gentle layer of fat. It was hardly noticeable, but Dash's figure definitely had a subtle softness that it lacked just the night before. Nopony would be able to tell that the Pegasus had gained weight without taking a very hard look though.

Rainbow Dash awoke with a yawn and took a moment to stretch, "That was a heck of a party, Pinkie."

"Thanks Dashie, although I might have to make more snacks next time. You almost chomped through all of the ones I made for last night," Pinkie replied. She had been fully alert ever since she exited her sleep.

Dash rubbed the back of her neck awkwardly, "Heh heh, yeah, sorry about that. I just felt starving for some reason. Speaking of that, I should probably do a bit of working out to day to make up for all those sweets."

Twilight nodded an agreement, "That's a great idea Rainbow. I'm sure we could all use some exercise. But how about we have breakfast first?"

"Eh, I guess a light meal wouldn't hurt to start things off...,"Came Dash's reply.

Pinkie Pie began jumping up and down at the idea,"Oooh,oooh, breakfast, of course! I'll get right on it. We can have Pancakes, and french toast, and WAFFLES too!"With that Pinkie disappeared into the kitchen, undoubtedly about to make a buffet of a breakfast. It wasn't long before she returned with giant plates filled with stacks of pancakes,french toast,waffles,and other assorted breakfast items.

Twilight stood up to excuse herself for a moment,"I need to go use the restroom, you two go ahead and start without me,"with that she turned around the corner and made sure she was out of sight before charging up her magic. It was likely that the spells she used on Rainbow last night had worn off, so she recasted them in order to prepare the rainbow pony for another round of overeating. After waiting a few moments Twilight returned to the table where her friends were sitting to find that Dash had already gone through at-least four waffles and four pancakes each, and was eagerly chowing down on a slice of french toast. By the time she had finished stuffing herself she had eaten twice as much as both Twilight and Pinkie combined.

Pinkie Pie seemed quite surprised, as it was rare for one of her friends to be able to eat more than her at any given meal, "That was pretty big for a light breakfast,Dashie."

Dash let out a half chuckle, half groan, "Yeah, I think I might of went a little overboard, I'll just have to up my exercise a little is all"

"You seem pretty full. Maybe you should wait awhile."

Dash ignored Pinkie's advice and got up out of her chair, "Nah, it's better if I get a quick start," with that she headed for the door, walking slightly awkwardly due to her overfilled belly.

Twilight paused for a moment in thought. It was unlikely Dash would be able to exercise very effectively after stuffing herself like that. On the other hoof, Rainbow was a determined pony and would likely be able to counter the experiment if left to her own devices. It wasn't hard for Twilight to form a plan to counter this however. "Pinkie, why don't you go and make some snacks? Just in case Rainbow Dash gets hungry in the middle of her big workout."

"That's a good idea Twilight. I know some perfect snacks to give an athletic pony lotsa energy."

As Pinkie bolted back off into the kitchen Twilight casted the spell to "empty" Rainbow Dash's stomach, ensuring that she would get hungry quite early on in her workout...

Twilight helped Pinkie bring out another plate of snacks just as Dash was coming in for the third break she had taken in just a few hours. There was barely enough time to set the platter down before Rainbow started consuming the tasty treats as if there was an incoming food shortage. It was hard to blame her though. The more Twilight practiced her hunger increasing the spell the more power she was able to pack in to it.

Pinkie had certainly noticed how ravenous her friend had become,"You're sure going through these snacks quickly,Rainbow."

Dash, seeming not fully aware of how much she had really eaten, brushed it off, "It's no big deal. I'm sure all the running and flying I've done out there has been more than enough to work it all off."

With that Dash got up from the table and headed for the door once again,while Pinkie began taking the emptied tray back into the kitchen. Twilight took a quick moment to empty Dash's stomach with her magic before following Pinkie Pie. Since the day started she had been helping Pinkie Pie with making snacks. She had told her it was part of an experiment to make food tastier, and that Dash was simply the taste-tester. What Pinkie didn't know however was that Twilight was adding secret ingredients that upped the amount of calories in the snacks by a very large amount.

It was a few hours and a few more high calorie snack breaks later before Dash decided to call it in for the day,"Thanks for making all these snacks and keeping me motivated, but I think I'm going to head home and relax now."

"See ya around Dashie,"said Pinkie as Rainbow Dash exited Sugarcube Corner and flew away.

With that Twilight decided she might as well head home as well and jot down some quick notes on her experiment so far,"I think I'm going to go back home too, Pinkie. Unless you need me to stay and help you clean up."

"Nah, I got it Twilight. Have fun with whatever you're off to do!"

Twilight left Sugarcube Corner shortly after and let her mind wonder to thoughts about the first full day of her experiment. She had to admit that it had went better than expected. While Rainbow Dash did get quite a lot of exercise, she had also unknowingly consumed an amount of fatty food so large that it would take multiple days of full workouts to burn off. If things continued at their current pace Rainbow would soon be showing some noticeable physical changes to record.

Author's Note

I realize the story's been a little slow to this point, but I needed to get the build-up out of the way. Things should stay pretty interesting from next chapter onward.

Early Effects

A few days had passed since the start of Twilight's experiment. She unfortunately hadn't seen much of Rainbow Dash lately, but from what she heard from others everything was still progressing nicely. It seemed that her appetite-increasing and metabolism-slowing spells, while both losing full effect after a few hours, were both leaving small residual effects that were building up the more she used them. Many of Twilight's other friends had talked about Rainbow Dash eating a lot more than usual the past few days and seeming to have less willpower whenever tempted with food.

Today Twilight would have a chance to observe the effects for herself, as the entire group was gathering together for a picnic just outside Ponyville. It would be good opportunity to continue pushing her experiment forward, as well as take note of any physical changes Dash might of gone under so far. Her saddle bags were full of high calorie sweets and other delectable desserts, it was her contribution to the picnic. Although she already had a good idea who'd be eating most of what she brought.

Twilight met up with her friends at their usual picnic spot. Everypony but Rainbow Dash was already there,and the picnic blanket had been laid out and covered with baskets brought by the others. Twilight levitated her own basket of food next to the others and set it down. "Has anypony seen Rainbow yet?"

Rarity should her head in response,"Not yet,dahling. I'm sure she'll be here soon."

It was only a few short moments after when Pinkie began shouting with excitement,"Here she comes! Now we can get started!"

Rainbow Dash swooped down from the sky and landed in the middle of the group, panting a little as she greeted them, "Sorry everypony, I've just been flying a little slow today. I think the extra exercise from the past few days must be wearing me down a little," explained Dash as she walked over to examine what food items had been brought.

Dash's explanation was certainly a possibility. Although the more likely answer was the apparent extra twenty to thirty pounds that was on her body. The usually athletic Pegasus now had a bit of pudge on various parts of her body. Her mid-section had lost any definition of tone, and now formed a soft pouch that stuck out a couple of inches. There were slight bits of fat on other parts of her body too, however the majority of Dash's gain seemed to be centered towards the back of her body. Her back legs had thickened considerably. Meanwhile her plot had rounded out and was now soft enough that it jiggled slightly as she walked. Twilight found herself strangely enticed as she watched that blue flank bounce a little with each step.

She shook her head, "Keep it professional Twilight," she thought to herself. Staying professional was a key part to any experiment, but Twilight's interest was starting to turn much more private. She focused herself and carefully timed the casting of her spell, making sure that Dash was hit with a ravenous appetite just as she opened a basket full of snacks. Dash seemed to be in her own world as she devoured numerous cookies, cupcakes, and other assorted junk food. Meanwhile her other friends merely looked on in shock. It was impossible not to notice Dash's new eating habits, and Twilight was sure the others had probably noticed the extra weight on Rainbow as well.

A sudden smirk came over Pinkie Pie's face as she walked over behind Rainbow Dash, "Careful Rainbow, all that sugar might go right to your FLANK!" To emphasize the last word Pinkie Pie landed a mischievous smack on Dash's flank, causing it to shake on impact.

Rainbow Dash jumped in surprise before turning around and glaring at Pinkie, "Why you little, come over here!" Rainbow Dash began chasing Pinkie all around the picnic area. The two circled around quite a few times before the chase came to a stop. Dash was quite unsuccessful in catching Pinkie Pie, and soon collapsed on the grass and started panting for breath,"Ugh..I must be more worn out than I thought." Meanwhile, Pinkie Pie just giggled at having gotten away with her improvised prank.

A look of concern crossed Rarity's face as she approached the winded Pegasus laying on the ground,"Dahling. I hate to sound insensitive, but have you thought that the reason you're running out of breath might have something to do with a little bit of weight that you've gained recently?"

Rainbow Dash looked herself over as she stood back up, "Yeah,yeah, I've gotten just a little bit out of shape. It's no big deal though. A few pounds are nothing for a pony like me to shave off. Now, don't we have a picnic to get to?"

It was nearly a half hour later and the picnic was still in full swing. Most of the six ponies gathered were full at this point and were just relaxing, all except for Rainbow Dash. She was still scarfing her way through the tremendous amount of food that had been gathered. Applejack shook her head slightly as she sat down next to Twilight, "Ah tell ya Twi, if Rainbow keeps eating like this she'll be as big as a barn by the end of the month."

"I'm sure she'll be fine. Everypony packs on a little bit of extra weight at some point," Twilight responded casually. Although there was a bit of truth to Applejack's statement. In just a few days Dash had already gone from the lightest of her friends to the heaviest, not by much though. Rainbow looked only slightly heavier than Pinkie, who was the next largest of the six. Although if she continued growing at her current pace it wouldn't take long for her to far surpass all her friends in weight.

Twilight continued to cast her collection of weight gain spells on Rainbow Dash until all the baskets of food had been totally emptied. At that point she had lost any hope of tracking how many calories her friend must of consumed, and her train of thought was derailed as Rainbow Dash leaned back to reveal her rounded, overstuffed belly.

Fluttershy double checked all the baskets, seemingly finding it hard to believe that Rainbow would of managed to go through so much food. "Oh my, well...at-least we don't have to deal with any left-overs this time."

Pinkie Pie, in contrast to the others, seemed more impressed than shocked,"You're getting pretty good at this Dashie, you should try competing in some professional food eating contests. I bet you'd knock them out of the park!"

Rainbow Dash paused in thought, "I don't know, I think I've been eating a little too much lately. I'll sleep on it for awhile. Anyways, that was a great picnic everypony, but I have a few things in town I need to do."

With that Rainbow Dash stood up and began walking back to town. All Twilight found herself able to do was stare at Rainbow's jiggling plot and think about how it was only going to get bigger from here on out...

Author's Note

This is all that I've written so far. I plan to start work on Chapter 4 soon though.

Hidden Motives

Twilight was in her study recording the latest notes on her experiment when she disrupted by the sound of a knock on the door from downstairs. It was probably Rainbow Dash, as the two of them had planned on having a sleepover tonight. Most of it would probably be spent discussing the latest Daring Do novels and such. Twilight also made sure that she had plenty of food on hoof for the occasion.

She heard the sound of light steps as Spike entered the room,"Twilight, Rainbow Dash is here. She also looks a bit..uhhh..different."

Twilight let out a sigh, doing her best to act surprised and concerned,"She's put on more weight hasn't she?"

"Oh yeah, definitely."

"Well, go ahead and let her in,Spike. I'll be down there in just a little bit."

It had been nearly a week since the picnic Twilight and all her friends had together, and it would soon be nearing the two-week mark for the experiment. She was fully expecting to see changes that were more dramatic than her last encounter with Rainbow Dash, but was still caught completely off guard as she descended the stairs and saw Dash waiting in the front room. Rainbow's figure had grown considerably. The most noticeable part was her belly, which had taken on a large and well-rounded shape. It protruded from her body so far that it hung down half-way to her knees. Even Dash's face had taken a little bit of the extra weight. Her cheeks puffed out just enough to give her face a cute, rounded form. Meanwhile a slight double chin had formed on her neck. Twilight couldn't get a good view on Dash's flank from this angle, but could still tell that it was definitely larger as well.

"Hey Twilight, what's up? You look a little out-there,"said Rainbow Dash, breaking Twilight out of her thoughts.

Twilight mentally slapped herself into focus and put on her best welcoming face,"Oh, sorry about that. I was just thinking on a new project is all. Anyways, I'm glad you're here. Go ahead and get comfortable. I'll be right back." With that Twilight exited into the kitchen where Spike had just finished putting a platter of snacks together. It was covered with cookies, chips, brownies, and other assorted foods.

"Twilight, are you sure it's a good idea to let Rainbow Dash be around all this junk food? Considering...uhh..." Asked Spike.

"Oh, don't worry about that. I'll make sure she doesn't eat too much. You did a good job,Spike. Go ahead and have the rest of the night to yourself."

Spike accepted Twilight's response with a shrug and headed off to separate room while Twilight re-entered the main room with the platter of snack goods. She sat down in a chair opposite of Rainbow Dash as she gently set down the plate on a table between the two of them,"I hope you didn't mind the wait. I was just getting some snacks in case either of us gets hungry this evening."

Dash eyed the delicious snacks with a look of temptation,"No thanks, I'm trying to lay off the calories for awhile...." Her spoken sentiment didn't last long,however. After biting her lip and eyeing the food for a few moments her tone changed,"Well, maybe one or two wouldn't hurt." With that Rainbow Dash grabbed a few cookies to chow down on, "So, have you got the new book?"

Twilight smiled as she levitated a copy of Daring Do and the Emerald Escape over to Rainbow Dash,"It just came in yesterday. I've already read some of it,but I'll let you read a few chapters and we can talk about it for awhile."

"Thanks Twi, you're the best," Rainbow Dash wasted no time opening the book and getting to her reading. Her immersion distracted her enough that Twilight could cast her spells as she pleased. Soon Rainbow was idly grabbing snacks of the platter and consuming them left and right. She seemed hardly aware of how much she was eating as each turn of the page also correlated with another couple of cookies or another thick fudge brownie. Twilight could only smile as the amount of food on the platter decreased and the amount in Dash's stomach increased.

After a few hours and a few refilled snack plates later Rainbow Dash was lying on the couch, her body partly covered with various crumbs. She had gone through a good portion of the new book but was unable to enjoy it further do to how overstuffed she was,"Unnghh...I think I had one too many brownies there.."Her speaking was interrupted by a small burp, "Twilight, how much did I eat?"

Twilight rubbed the back of her neck and put on a thoughtful look,"Hmm...maybe a couple platters full? It's nothing to worry about though, I made sure to put in small portions."

"You call those small portions? I feel like a stuffed pig right now,"Dash groaned.

Twilight chuckled nervously,"Well, perhaps next time we'll go with even smaller ones. Anyways, it's getting pretty late. You feel ready to go to sleep?"

"Definitely, I think I might just stay here on this couch if you don't mind."

"Alright, I'll be upstairs if you need anything," With that Twilight headed back to her room to take a couple more notes in order to give some time for Dash to fall asleep. After about a half-hour she quietly walked back downstairs again. She peeked her head around the corner to see Rainbow Dash fast asleep. She was lying on her back, which quickly attracted Twilight's eyes to her potbelly. It was so perfectly round and stuck out from her body enticingly. However, Twilight decided it might look even better if it were a bit bigger. There wouldn't be anything wrong with helping that happen either. Twilight prepared her usual assortment of weight gain spells, but this time let them charge up for added effect. After casting them she quickly went back to her room knowing that Dash would soon awaken with massive hunger.

Sure enough it was only a minute or two after Twilight jumped in her bed that Rainbow Dash entered the room,"Hay Twi. I hope I'm not waking your or anything..."

Twilight put out a fake yawn before answering,"No, I wasn't really that much asleep yet. What do you need?"

"I'm really starving for some reason. Is there anything I could have for a light midnight snack?"

"There should be some left-over snacks in the fridge and pantry, just clean up any mess when you're done."

"Thanks Twi, can do." With that Rainbow Dash turned around to walk out. This gave Twilight a perfect look at her large,supple rear. There's was no way Twilight could prevent herself from being slightly entranced by the heavy jiggling of her friend's plot. Twilight waited until Dash was out of view before laying back down to actually go to sleep. She knew that she'd probably have to make an expensive trip to the grocery store tomorrow. However, it would be worth it for the all the food consumed tonight by Rainbow Dash would soon contribute itself to a very good cause.

The Next Stage

Twilight was deep in her thoughts as she walked through Ponyville. It had now been almost a month since the start of her experiment. She had to admit that things had gone better than she could of ever expected. Rainbow Dash had been gaining steadily. In addition, Twilight's weight gain spells seemed to be getting more effective all the time. The magic expo wasn't for another month and she was already near guaranteed to win.

She had made sure to finish up all her notes early since it was going to be a big day. It was Rainbow Dash's birthday, and as usual Pinkie Pie was throwing a huge party. Like a typical Pinkie Party there was going to be calorie rich sweets everywhere. It was the perfect stage for Twilight to continue accelerating her experiment.

Twilight entered Sugarcube Corner with great excitement. Everypony was there. Including Rainbow Dash's other four best friends,Spike, and some other assorted guests from Ponyville that Pinkie Pie had invited. Now they just had to wait for the guest of honor.

Twilight was approached by Pinkie Pie, who seemed more excited than anypony,"Twilight! You're here! We're almost ready now."

"I've got to say Pinkie, you've done a great job setting this up," Twilight complimented as she took a look around Sugarcube Corner. The entire place had been transformed with vibrant colors and decorations. There were more balloons than ponies. Most importantly, there was an over abundance of party food. Not only was the main counter covered with food, there were several tables full as well! Under normal circumstances a lot of this would end up going to waste. Considering who the party was for though.....

"Thanks Twilight," Pinkie replied,"Feel free to sample some of the food. Just don't eat any of the giant cake I have stashed behind the counter. We need to save it for Dashie."

Twilight nodded as she strolled over to the main counter. Eyeing the assortment of delectable brownies,cupcakes,cookies, and much more. She grabbed one of the cupcakes and took a bite. She was immediately awarded with an intense flavor of chocolate mixed with cherry. A similar taste test of the other categories of treats revealed them all to be equally tasty. Twilight herself could barely resist the food here. There was absolutely no chance of Rainbow Dash having the willpower to resist.

"Dashie's coming everypony, get ready!" Pinkie Pie shouted.

Twilight quickly found herself some cover behind a table as Pinkie Pie shut off the lights. A few moments later the door opened to reveal Rainbow Dash. This led to Pinkie Pie flicking on the lights and everypony leaping out of their hiding spots to yell "Surprise!". Twilight joined the rest of her friends in walking up to Rainbow Dash to congratulate her up close.

"Happy birthday Dashie!"Chimed Pinkie,"This is gonna be the best party ever! We've got a giant cake, and we're gonna have a pinata, and games! Lots and lots of games!"

Rainbow Dash laughed happily, "Thanks Pinkie. This looks really awesome. I'm not even sure where to start."

"Well, ah'll let you have the run of the place first, but sometime ah gotta take ya on for that eating contest rematch. Ah probably lose, but ah gotta try,"challenged Applejack.

Rainbow Dash looked as confident as ever, "You're on."

While the others were busy talking with Rainbow Dash, Twilight took it upon herself to examine Dash's ever expanding form. Her belly hung down just a little past her knees, and wobbled like jello when she moved. Her neck had thickened quite a bit. Leaving her with an undeniable double chin. Her front legs seemed to be following the example of her rear legs and were plumping up as well.

"Well, better not waste any time. I've got a lot to do!" Rainbow Dash stated.

"Right, Dashie,"agree Pinkie before addressing the whole crowd, "Let's get this party started!"

All the energy that had been building up before the party exploded. Soon the room was filled with the loud sounds of ponies partying as all the guests sought out ways to entertain themselves. Meanwhile, Rainbow Dash began waddling towards the counter. This gave Twilight a perfect view from the back. Rainbow's thighs were extremely thick. To the point where they were rubbing together constantly. However, this was nothing compared to the amazing growth of Dash's flank. Two large, round,and soft plot cheeks curved out the rear of her body. Her rump didn't just jiggle, it bounced. Every step caused that rear to shake enticingly. Twilight had to close her jaw and keep herself from drooling as she began to fantasize. How lovely it would be to caress and rub that soft,squishy flesh...

"Twilight!"

Twilight jumped slightly as her day dream was interrupted. She saw Pinkie Pie standing in front of her, looking a little curious. "Huh? What is it, Pinkie?"

"Were you staring at Dashie's flank?"

Twilight could feel her face turn hot as she stammered for words to cover herself,"W-What? No, of course not! I was just..uhh...I..."

"Pffft, you were! Don't worry Twi, I won't tell anypony,"Pinkie assured Twilight with a wink before going over to Rainbow Dash's side to suggest what flavors of sweets to try first.

Twilight let out a sigh of relief."That was a close one". She had to be more careful. If Dash would happen to catch her getting so enthralled she might start to get suspicious.

Meanwhile at the counter Rainbow Dash was getting well acquainted with the assortment of sweets created in her honor. She first confronted a plate of cupcakes. It started with just one bite of a blueberry capcake. Then that bite turned into the entire cupcake being shoved into her maw. Before long she had consumed the entire plate, filling her mouth with several cupcakes and a variety of fruity flavors. She had already consumed more than any other pony at the party and wasn't even close to feeling full. She quickly moved on to a plate full of cookies, shoving down nearly a dozen in just a few minutes. It wasn't until a half plate full of thick,creamy,double fudge brownies later that she started to feel full. She was ready to call it good when just shortly after stopping she felt a sudden emptiness in her stomach. It seems she still had more room left than she thought. Before she had time to question it Pinkie Pie went behind the counter and pulled up what had to be the most delicious looking cake Dash had ever seen.

Hefted on to the counter was a towering,quadruple layered chocolate cake. Just the look off it was irresistible. It was made to seem even better by Pinkie Pie's following commentary,"Here's your birthday cake, Dashie. Four layers made up of three different kinds of fudge, mixed with chocolate icing and plenty of cream on the inside. I hope you like it."

Like didn't begin to describe it. Rainbow Dash was practically drooling as she stared at the cake in front of her. It took all of her restraint to stop from simply shoveling hoof-fulls of it into her mouth. As soon as a plate was set in front of Rainbow she immediately put two large slices of cake on it and began going to work. Every bit of fudge that hit her tongue only made her more ravenous. Soon the first slice was gone, then another, and another. At first glance Dash thought she wouldn't of had a chance at taking on this cake alone, but she was already a quarter through it! It seemed that whenever she was close to getting full she somehow managed to find enough room to keep eating. Slice after slice found it's way down to her belly until very little remained of the once impressive cake.

Pinkie Pie looked at Rainbow Dash with awe, "Wow,Dashie. That's gotta be a record! I wonder if there's awards for this kind of thing!"

As much as Dash hated to admit it, her eating had been getting a lot more faster than her flying as of late. She still felt slightly pleased with herself,however.

"Wow,Rainbow. That was mighty impressive,"complimented Applejack as she walked over,"Ah was gonna ask if you'd join me and some other ponies for an eating competition, but it looks like you might of had yer fill already."

Dash didn't consider sitting out for a second,"Pffft. Are you kidding? I can totally keep going. There's no way I'm going to sit out of a competition, especially one I'm sure to win."As much as Rainbow was dissatisfied with how large her gut had become, it did come with a few perks. She heavily doubted that any of the other ponies at this party could even come close to eating more than she could.

Rainbow Dash followed Applejack to a line of tables stacked with all kinds of treats and moved to sit in the remaining open chair. The chair squeaked and groaned from Dash's weight as she sat down. Her plot squished outward and actually stuck out past the chair. Normally these type of wooden seats would be uncomfortable but her flank now had so much padding she hardly noticed.

She could barely contain herself as she waited for the start. A large stack of various flavored pies and mini-cakes directly in front of her. As the whistle blew signalling the start she immediately dove right in. She grabbed a pie in each hoof and consumed one in just a few strawberry filled bites. The other pie didn't last long either. It's blueberry wonder was quickly sent on it's way to Dash's belly. She didn't even bother to keep tabs on the progress of her opponents. She simply kept focused on absolutely destroying the pile of food in front of her. About half way through she started to slow down only to receive a second wind. Later she caught a third wind,a fourth, and so on. Soon all the food in front of her was gone. It wasn't until now that she realized she had won the contest a long time ago and had simply been gorging herself since then. The other guests cheered and clapped at her victory. Meanwhile, she simply laid back and rested a hoof on her rounded mid-section.

The party went on for the greater part of the afternoon before things started winding down. Aside from helping her experiment along, Twilight spent much of the time gauging the reaction of her friends to Rainbow Dash's changes. Applejack and Rarity seemed the most concerned about it, but both of them were too polite to say anything more than a passing comment or suggestion. Pinkie Pie seemed indifferent or almost amused by it all. Fluttershy,however, was difficult to read due to her shyness and withdrawn nature. All things considered, Twilight doubted that any of her friends would act enough to influence Rainbow Dash or the experiment.

As the party ended guests start slowing filing out. Twilight followed Rainbow Dash and the rest of her friends outside to say good-bye before parting ways for awhile.

"Thanks for the party,Pinkie,but I better be heading back home,"Said Dash as she turned and positioned herself for take off, unintentionally sticking out her large plot towards the group. A barely detectable "eep" came from Fluttershy,who appeared to be blushing as well. Rainbow managed to only get a foot or two of the ground before she collapsed. All the bulk on her body shook as she made contact with the earth. She wasn't going to give up easily though. Rainbow tried multiple times to take flight. However, no matter how hard she tried each attempt ended in her being pulled back down to the ground. Twilight also noted how Fluttershy seemed to be staring quite intensely at Dash's body and how she blushed deeper each time Rainbow's mass jiggled on falling to the ground."It seems I'm not the only one with some unique interests," Twilight mused to herself.

After about the fifth try Rainbow Dash simply laid on the ground and panted heavily. Her fur was now drenched with sweat from all the effort. A few moments later she slowly got up and looked at the ground with sadness,"I can't believe I let myself go this far."

Fluttershy quickly moved to comfort her,"Aw, don't get too upset,Rainbow Dash. I'm sure you'll work off a few pounds in no time and you'll be flying like normal again."

"Well,sure,"Rainbow Dash agreed,"But where am I supposed to stay in the meantime?"

Twilight wasted no time jumping on this new opportunity,"Don't worry about that,Rainbow. You can come stay with me until you get your flight back,and I'm sure Fluttershy can fly up to your house and get Tank for you,"Fluttershy nodded in response to Twilight's idea. To Rainbow Dash it probably sounded like a selfless offer. Twilight's motives ran quite deeper,however. She figured it would be much easier to conduct her experiment when the test subject was staying inside her own home. It may even open the door to push things further at a higher rate.

About a half hour later Twilight and Rainbow Dash arrived at Twilight's library. Rainbow Dash's first action was to lay down on the couch. She was clearly still depressed from the loss of her flight earlier. Twilight had to admit she was feeling a slight amount of guilt over it, but it was all only temporary. In about a month the experiment would be over and she could undo everything. Besides, she had already come too far to stop now.

"Thanks again for letting me stay,Twi. I'm sure it won't be for too long,"said Rainbow Dash.

"Think nothing of it,Rainbow. You can stay as long as you need. Now I'm going to make some dinner, you want anything?" Twilight offered.

"Nah, I think I've had enough food for today."

Twilight trotted into the kitchen, getting to work on assembling a large amount of hay burgers. Rainbow Dash might think she's had enough food, but there were ways to change her mind. From the privacy of the kitchen Twilight cast a quick spell to rejuvenate Dash's appetite. Sure enough, Rainbow Dash entered the kitchen not long afterwards.

"Hey Twi, I changed my mind. Think you can make me some of those burgers? I need a bit of comfort food right now."

Twilight smiled in response,"Sure thing,Dash. Coming right up."

Not long later a platter filled with nearly a dozen hay burgers was set down in front of Rainbow Dash in the living room,"You're a really great friend for doing all this,Twi,"Rainbow Dash said in gratitude,"Tomorrow I'm going to take my workout to the next level and show this belly who's boss. For now though, I'm just going to enjoy all this food."

Author's Note

I put effort into adding extra detail on this chapter, since many had advised me to slow the pace a little. Comments are welcome as always.

The Wild Card

Author's Note

Sorry this chapter took so long. Life got in the way for awhile. The next chapter will probably be the final, but I'm thinking about writing an alternate ending or two after that depending on demand. Anyways, enjoy!

Also, the early part of this chapter gets a bit questionable. But there's no outright nudity or sex, so hopefully the Teen rating still covers things.

The Wild Card

"Come on Rainbow, we don't want to miss the train!" Twilight called out. Today was going to be a big day. The entire group was going to be heading out for another trip to the big city of Manehattan. They were going to be gone for a couple of days, so Twilight was leaving Spike behind to watch after things. She didn't like leaving her assistant alone too often, but was confident he'd be alright. "Rainbow Dash, we're running out of time!" Twilight called again.

"Alright,alright. Just hold on a minute.", Came Rainbow's voice from the kitchen, "I'd like to see how fast you'd move if you had all this bulk.", said Dash as she waddled into the main room. Despite her attempts at exercise Rainbow's figure had been suffering a continuing toll these past few weeks. Her belly now hung down well past her knees, spreading her legs apart and forcing her to waddle wherever she went. The space between Rainbow's gut and the ground seemed to be getting smaller by the day.

"I'm sure you'll get it under control soon, but we need to get going.", Twilight made a last minute check to make sure she had everything in her saddlebags. She soon heard Rainbow Dash letting out frustrated grunts and looked up to an interesting sight. Rainbow had become stuck in the door! Her flank and hips were so wide that they managed to become wedged in the door frame.

"Uhhhh....Twilight.", Rainbow said nervously, "I think I'm stuck."

Twilight's response was delayed, as for a time she stood awestruck at the sheer size of Dash's rear, but she soon called herself back into reality. "Not to worry, Rainbow. I've got an idea to get you free."

She went up stairs to fetch some lubricant and quickly returned to the main room. She could barely stop herself from shaking in anticipation as she dipped her hooves in the lubricant and prepared to attend to Rainbow's stuck rump. She than began to slowly rub the slick fluid over the sweeping,round curves of Rainbow's plot. This didn't go unnoticed, however.

"Twilight, what are you doing back there?" Rainbow called back nervously.

"Getting you unstuck.", Twilight replied, hiding her excitement at finally getting to put her hooves on Rainbow's giant,soft rump.

"Couldn't you use some kind of magic for this?"Rainbow asked, undoubtedly feeling a bit awkward.

"Well I could, but it wouldn't be as much fun.", Twilight mused to herself. "Don't worry about it, Rainbow. You'll be out of here in no time." She then turned her attention back to the massive rear before her. She felt her hooves often sink in to the soft flesh of the vast cheeks that she was lubricating. She briefly went over Rainbow's cutie marks, which were now three times their normal size and easily bigger than Twilight's face. She then roamed to the lower part of Rainbow's flank and put her hooves underneath the over-sized plot cheeks for the sake of feeling just how heavy they were. She could probably squeeze Rainbow Dash through the door now, but part of her didn't want to stop.

This was one situation that Rainbow Dash never thought she'd find herself in. Of all the things that could of happened she had to get her butt stuck in a door. Had she really gained THAT much weight? Admittedly her work-outs could be going better but she still couldn't understand how she was packing on the pounds so rapidly. If her frame became any larger it could start becoming difficult to get around. Disturbing as the situation was though, she had to admit there was a few perks. During the past few months she'd been able to enjoy food like never before. In addition, her new figure had earned her a sort of extra attention that she wasn't used to. Her belly and rump seemed to mesmorize some ponies with their new size wherever she went. Speaking of attention....

It was impossible to ignore how vigarous Twilight was getting with her flank. She wasn't just rubbing some sort of liquid over her rear, she was practically massaging it in. It didn't feel bad though, it almost felt kind of good. Rainbow heard a slight moan escape her lips before she snapped herself back into focus. She was stuck in a door, with a flank big enough for smaller ponies to nap on. This wasn't something she should be enjoying, even if it did feel a bit soothing.

"You ready, Rainbow?" Twilight called from inside.

Rainbow Dash sighed, "Yeah, let's get this over with."

Soon she could feel the impact of Twilight attempting to push her the rest of the way through the door. She did her best to help the effort and tried to pull herself free. It wasn't easy, but after a lot of Twilight mashing her plot cheeks together and shoving hard Rainbow managed to get free of the door. Her huge rump now jiggled and bounced everywhere since it was no longer restrained.

Twilight walked in front to where Rainbow Dash could see her, wiping away some sweat as she spoke. "Phew, that was certainly interesting. We better rush to the train station now."

Rainbow Dash nodded, "But...uhhh, Twi. Could you do me a favor? Let's not say anything about this to the others."

Twilight smiled, "Of course, but, you may want to be careful with smaller doors from now on. Wouldn't want this to happen while we're in the big city."

The two managed to reach the train station just in the nic of time. Meeting up with the rest of their friends they boarded the train, with Rainbow Dash having to carefully wedge herself through a couple doors on the way. Rainbow found herself taking up two entire seats and even then her wide plot squished out over the edges a bit. She did her best to get comfortable as the train ride began, but it was made difficult by the fact that every bump off the train sent her fat jiggling everywhere. She was grateful when Rarity started up a conversation, giving her something else to focus on for awhile.

"Dahling, do you think you could do me a favor when we reach Manehattan?" Rarity seemed somewhat nervous about the question she was asking, prompting Rainbow to probe for some details.

"What sort of favor?"

"Well...you see, Photo Finish has been in need of a.." Rarity paused, attempting to choose her words carefully, "Really plus-sized model, and if you agree to pose for a photo shoot it will really help me get in her good graces."

"What? No way! I'm trying to lose this weight, not show it off," Rainbow said in rejection.

"I know, Dahling. But if you'll agree to this I'll help you with your weight loss. I've had to learn a thing or two about it in order to maintain my figure despite not getting much exercise. So what do you say?"

Rainbow took a moment to think it all over. She wasn't very keen on the whole modeling idea. On the other hoof, she needed all the help she could get at this point. Her work-outs hadn't been doing the trick and she had gotten so large that even moving around was becoming a major burden. She needed to stop her gaining fast or she might be beyond help soon. "Ughh....fine. You got a deal, Rarity, I'll do it."

"Excellent, Pose. Now turn around, very good so far."

"I still can't believe I'm doing this", Rainbow Dash mused to herself as she turned around and pointed her giant rump to the camera. For what seemed like an hour she had been striking various poses for the camera, showing off the largeness of each part of her body. Next she was command to sit down so the next photos could focus on her belly. She did as ordered and soon her massive gut took up a good portion of her view. It was about the size of an over-inflated beach ball, and Rainbow now longer had any chance of seeing her belly-button.

It was about another fifteen minutes of posing before Rainbow Dash was freed from the task. Photo Finish glowed about how popular this shoot would become before allowing Rainbow to take her payment and leave, meeting Rarity on the outside.

"Well Dahling, how did it go?" Rarity inquired.

"It went fine," Rainbow quickly answered,"But I'm just glad it's over. Where's the others?"

"They're waiting for us at a diner just down the street."

"Awesome, I could use some light dessert to get my mind off things."

The two walked together to a semi-classy looking restaurant not far down the street where they were greeted by all their friends. The group decided to seat themselves in a large booth. As was to be expected Rainbow Dash took up one side of the booth all too herself, while her friends sat in smaller chairs opposite of her. Taking up part of an entire booth wasn't Rainbow's only problem however, as she found her belly too large to wedge in between the back of the seat and the table. Due to this she was forced to prop her heavy gut on top of the table, it squished out to take up nearly half the surface and the table groaned underneath the weight of the belly it was now being forced to support.

Menus were brought out to them and the group began to look over the diner's choices. It was Twilight who found the most interesting part of the menu. A special deal that whoever could win the restaurant's eating contest would earn a free meal for themselves and their entire group. The contest required that a single pony eat the entirety of the restaurant's "Mega Cheese Monster Pizza," it was a cheese pizza so large they had to set it up on a separate table. Twilight knew the perfect candidate for that job. She quickly pointed out the contest
to the rest of the group.

"The sounds like a mighty fine deal," Applejack stated in agreement, "But it says one pony has to eat it all. I know my stomach sure ain't big enough. I'm not sure any of us could handle it."

"Umm..."Fluttershy said meekly, "Well, there's one of us who might be able to..."

All eyes nervously turned to Rainbow Dash. She immediately knew what they were thinking and shook her head in denial, "Nuh-uh. I came here for a light dessert, that's it. You know how many calories must be in a pizza that size?"

"But Rainbow, you're the only one who can do it. Besides, you wouldn't want to turn down a challenge would you?" Twilight stated in attempt to persuade Rainbow Dash.

Fluttershy nodded in agreement, "It says right here that nopony has ever done it before. You could be the very first. It would probably make you famous around here."

Twilight and Fluttershy's points made Rainbow take a moment to consider. While she did her eyes also drifted to the picture of the over-sized pizza on the menu. It looked extremely delicious, and it almost made her drool to think about eating it. Soon her competitive nature and her over zealous appetite worked together to crush any resistance she had to the idea. "Oh, what the hay? I'll give it a try."

With that the challenge began. Rainbow Dash's acceptance of the challenge was relayed to the kitchen and before long a massive cheese pizza was brought out to a nearby table. It was without doubt the largest any of the group had ever seen, and there were doubts that even Rainbow would be able to consume all of it. She was willing to try, however, and her friends did what they could to assist. They were constantly fetching more slices to put on small plates to bring to Rainbow. It was difficult for Rainbow Dash to reach the table in front of her, so she sat the plates on her own belly instead. Normally it would bother her that her gut had become large enough to serve as a table, but she was too distracted by the endless flow of delicious pizza being delivered to her. It was like a cheese filled heaven, no matter how much she ate there was another slice ready to be devoured.

As Rainbow's feast continued the gigantic pizza began to slowly shrink down, slice by slice. At the same time Rainbow's belly began to bloat slightly from the sheer amount of food she was eating, but yet there was no signs that she would be ready to quit anytime soon. Meanwhile, the weight that Dash was putting on the table began to increase as well. It began to creek and groan with growing frequency, being strained to the point where cracks started to appear in the wooden frame. The table was spared from an untimely fate though as Rainbow managed to force down the final slice of pizza. Her friends and other ponies around the restaurant began to cheer and clap at the incredible feat they just witnessed.

Twilight trotted over to the almost broken table, trying to keep from staring at Rainbow's now swollen belly. "Congratulations, Rainbow. You did won and that means free food for all of us. Anything you want?"

Rainbow thought about it as she tapped her heavy mid-section, "Hmm...well I guess a little dessert couldn't hurt."

"Why am I always the one who gets left out?" Spike complained to himself as he began sweeping the floor in Twilight's room. He still couldn't believe that Twilight and the rest of the group got to take a trip to Canterlot and he was left behind to do a bunch of menial chores. Sometimes it felt like he was always getting the short end of the stick for some reason.

He grumbled to himself further as he continued the work, and got so distracted by all of it that he bumped into Twilight's desk. The impact caused a large stack of papers to tumble down on to the floor. Spike shook his head and mentally chastised himself for the clumsiness. "Now there's another thing I have to clean up."

He reached down to pick up the papers and noticed the headline, "New Experiment" on one of them. Suddenly a great temptation rose to read further, although he knew he shouldn't be looking at Twilight's writing. It was none of his business after all. On second thought, Twilight would never have to know he read it. Temptation won out and he picked up a few of the papers to read. The words written down were far from anything he expected, however. Shock began to run through him as he discovered what Twilight's new experiment was. "That's why Rainbow Dash has gained weight so fast, and it's why Twi has been acting so strangely. Oh no, this isn't good." The information immediately left him torn. He didn't want to betray Twilight, but he couldn't just let her keep using Rainbow Dash as a lab rat.

He had to do something, but what?

Conclusions

Author's Note

After insanely long wait it's finally here: the last chapter. College plus other commitments made it really hard to create time to finish this. I do hope to create another story in the near future if I get the time and motivation, don't know what that next story will be though.

Anyways, thanks to everyone who's read this, hope you enjoy a quick little finale.

Conclusions

Twilight trotted home in absolute disgrace. The falling rain easily matching her mood. She had just finished up at the magic expo, where she presented the results of her experiment. It seemed to be going well; until they banned her for "unethical practice". However, since Twilight's spells technically hadn't caused any harm and there were no specific rules against what she did they were unable to go any further than that. Even if they could, those in charge decided it would be better to just kick Twilight out and cover the whole thing up to avoid attracting controversy.

Perhaps it was for the better though. She didn't have to worry about it anymore. Although, there was still the nagging issue of what to do about Rainbow Dash now. Twilight had yet to find any spells to reverse the ones she had been using the entire time. So it was likely that Rainbow would just have to lose the weight on her own. "As long as she doesn't find out I'm the reason she got so huge in the first place, I'll be fine."

She entered her library with a sigh of both exhaustion and relief. She was home, the project was done, and now it was time to move on to something else. She soon found Rainbow Dash laying on the new couch that was purchased before Twilight left on her trip. Rainbow had become too large for most normal furniture to handle. A couple broken chairs served to drive that point home. It wasn't hard to see why this was the case; Dash herself was large enough to be a couch. She opened her eyes as Twilight walked in, smiling as she spoke, "Hey, Twi. How was the big trip?"

"It went great,"Twilight responded while putting on a fake smile and biting her lip slightly, "Absolutely perfect."

"That's good to hear,"said Rainbow Dash as she slowly got up from the couch, grunting as she struggled to lift her massive frame. At this point she was probably one of the heaviest mares Twilight had ever seen. Her gigantic, round,bulbous belly stretched so wide that it forced all four of her legs to take a wide stance. It also hung so low that it seemed to be slightly grazing the ground. Rainbow's flank had continued the trend of outpacing her flank. Her rear and hips had grown so large that Twilight could see them bulging out even while being in front of Dash. All together Rainbow Dash was a lovely sight to come home to. It was a shame the experiment was over now, but at-least the results were spectacular.

"Anyways, I'm going to go grab a quick snack," Rainbow Dash broke the silence as she begin slowly hauling herself across the room. Her entire body shook and wobbled with every small step. Twilight became so enthralled that she was caught completely off guard when Rainbow swung her lower body around with surprising speed and force; knocking Twilight into a nearby wall.

Twilight rubbed her head while trying to regain her senses, "Owww, Rainbow! What was that f-", her protest was cut off as she saw Rainbow Dash backing up towards her. Rainbow's titanic, blue flank was beginning to overtake her entire frame of view. Realizing the dilemma, Twilight attempted to use her magic to push Dash away. However, Rainbow was far too heavy and Twilight far too stunned. Soon she found herself being engulfed by thick flesh as Dash slowly laid down on top of her. Rainbow's belly pinned down most of Twilight's body, while Twilight's face was squished directly between two humongous flank cheeks. She reached out her hooves to try and push Rainbow Dash off, but found nothing but more and more soft flesh. There didn't seem to be any end to the rump that was trying to squash her.

"I know about your plans to turn me into Rainblob,"said Rainbow with a bit of snarl. She certainly sounded angry, but there was a hint of mischief as well. She had Twilight right where she wanted her. "You got pretty close, but the experiment's over. Now it's time to reverse all this."

Twilight knew for the sake of getting oxygen it would be best to agree to Rainbow's demands. However, part of her was enjoying this. It felt so amazing to be surrounded by a flank that was so huge and round, and so plush. If only she had a breathing spell to cast on herself she could spend all day burying her face and hooves into the endless expanse of Dash's rear. In the end her desire for air overcame her lust as she tapped on Rainbow's flank in submission.

Rainbow Dash lifted her body up just slightly, giving Twilight enough space to start catching her breath. "Alright...*pant*...you win, Rainbow.."

"Good. So reverse all of this."

Twilight carefully worded her response, "Well, I don't actually know how.."

Rainbow Dash apparently didn't like that answer, "Then you better get ready to take another plunge."

"No, wai-!" Twilight's protest was cut off as she was once again submerged in Rainbow's massive flank cheeks. The two giant oceans of blue flesh overwhelmed her senses and took her breath away in more ways than one.

"I'm not even putting my full weight down" Rainbow Dash said in a mocking tone, "Just imagine if I did though." To emphasize her point, Rainbow put a slight bit of pressure on Twilight. Twilight gasped as she felt the air being pushed out of her. She began to fear she would suffocate like this, but at the last moment Rainbow Dash picked her body up again. "So, I hope you thought hard about what I asked you, because I'm getting kind of tired and you make for a nice bed..."

Twilight composed herself and heavily thought out her answer. "Okay, Rainbow. I'll figure out how to reverse the damage. Just please...let me breathe for awhile."

"Good enough for me," said Rainbow Dash as she gave Twilight a bit of space and turned around.

"There's just one thing, Rainbow,"said Twilight, "How did you find out?"

Rainbow Dash stepped out of the way, revealing a very flustered looking Spike. "I'm real sorry Twilight, but I just had to tell her. When I found out what you were doing...I just..."

Twilight sighed, "No,Spike. It's alright. I deserved this. Rainbow Dash, I'm sorry. I was wrong to use you the way I did. Could you forgive me?"

"Well, we'll see how my new weight loss goes," Dash answered, "If it works out, we're cool. But if I'm still packing on pounds, I'll turn you into Twilight pancake."

The teasing note in Rainbow's voiced made it impossible for Twilight to tell if she was joking about that threat or not. It was a shame Rainbow Dash's beautiful new figure would soon start slimming down, but Twilight at-least would have the pleasure of watching a massive, round belly; and huge,sweat-drenched flanks bouncing and wobbling everywhere during Dash's exercise. Plus, who knows? Perhaps the time would come for a new experiment someday...

The Experiment Succeeds (Alternate Ending/Bad End)

Author's Note

So after three years (Can't believe it's been that long), I finally decided to return and write an alternate ending for this story. I feel my writing has improved a lot since I started and I was able to give this the detail that the rest of the story deserved.

Fetish warnings: Fat/Weight Gain (Obviously), forcefeeding/stuffing, hypnotism/mind-control, immobility, and a really big blob-sized Rainbow Dash. Potentially a tad bit on the dark side depending how sensitive you are.

Final Note: This is the most fetishy of all the chapters so I changed the rating from Teen to Mature just to cover myself.

The Experiment Succeeds (Alternate Ending/Bad End)

Pant “Another…” Pant “Successful workout”, Rainbow Dash declared through her heavy breathing as she slowly waddled through the recently expanded door to Twilight’s house. Although Rainbow Dash was confident in her new workout regime, the fact that the sides of her flanks were grazing against the sides of the door frame once again was proof that she wasn’t getting any thinner.

“You’ll be shedding those pounds in no time, Dash,” Twilight replied somewhat distantly. She was far too busy staring at the circus show that was Rainbow’s ass. Those two cyan blue flank cheeks were constantly bouncing and grinding against each other, each one big enough to serve as a chair. Their only competition was Rainbow Dash’s massive belly, which swayed with her steps and had begun to slightly graze the ground. Twilight shuddered with excitement as she realized that her test subject was only about ten to fifteen pounds away from immobility.

“Just a little more,” Twilight mused to herself. Although she had been kicked out of the science competition, she had resolved to continue her little experiment. In the past few weeks since she returned, she had enjoyed refining her methods and watching Rainbow continue filling out to new sizes. Even as Rainbow Dash was exercising harder than ever, Twilight was able to use her sneaky techniques to stuff her full of enough calories to negate any weight loss.

Twilight’s thoughts were interrupted by the sound of creaking as Rainbow Dash laid her massive body out on the living room couch. Twilight had recently filled the house with reinforced furniture, but even that almost wasn’t enough to handle Rainbow’s pure size.

“Hey, Twi?” Rainbow asked, still panting very heavily.

“Yeah, Dash?”

“I’m really beat. Could you get me something to drink and a small snack?”

Twilight smirked, “Sure, Dash. Just a second,” Twilight happily trotted into the kitchen where she met with Spike.

“Hey, Twilight. I’ve almost finished preparing the list of food you made. Is the plan still a go?”

“Definitely,” Twilight replied as she looked Spike’s handiwork over with satisfaction. While she had kept Rainbow Dash distracted with futile exercise, Spike had been preparing a calorie filled feast for the ages. The kitchen had been filled with cookies, cakes, pies, and several other forms of fattening desserts, “I think we’re finally ready to push Rainbow over the edge. Once she’s restricted to her bed, she’ll grow faster than anypony’s ever seen.”

“Just how big are we going to get her?” Spike asked with curiosity.

“I’m not sure yet. I’ll have to shrink her back down eventually, but not anytime soon.”

“Right, well let’s get to work.”

Twilight nodded, “Thanks for going along with this Spike. I had no idea you shared my interests.”

Spike blushed, “As long as I get to help feed and play with her.”

“Of course. Now let’s go, we have a mare who needs growing.”

Twilight and Spike made their way into the living room with a giant platter of chocolate chip cookies in tow along with a massive jug of chocolate milk. Rainbow’s eyes lit up and she began to drool, but she seemed to shake it off.

“There’s a part of her deep down that enjoys this, I just have to make it the dominant part of her,” Twilight mused.

“Uh, Twi...I said a small snack..” Rainbow said.

“No problem, Dash,” Twilight replied, “Just eat into your full. We’ll save the rest for later.”

“Well, alright,” Rainbow answered as she carefully reached out and grabbed a cookie. The moment that chocolate chip goodness hit her tongue it seemed to trigger something in her. She quickly scarfed it down and reached for a second cookie, and then a third.

“Mmm...these are really good you two. Just a few more..”

Twilight and Spike watched with approval while Rainbow Dash continued stuffing her face with cookies. There was something strangely arousing at seeing this mare eat, knowing that all the sugary calories she was consuming would cause her belly and plot to grow bigger, rounder, and bouncier.

Soon the entire platter was empty, and Rainbow Dash grabbed the jug of chocolate milk before rapidly chugging it down. She let out an audible burp after emptying the container, “Wow. That was something. I might have gone a little overboard,” Rainbow said with a small giggle, “I’ll just have to eat light for dinner. Not going to lose this giant belly at this rate,” she gave her expansive gut a smack for emphasis. Twilight and Spike both had to hide their respective arousal as Dash’s massive middle jiggled and wobbled like jello. That blue dome of a belly was like a huge exercise ball, capable of holding multiple meals worth of food.

“Are you sure you’re finished, Rainbow?” Twilight asked as her horn lit up. Soon after a loud gurgle was heard from Rainbow Dash’s stomach.

Rainbow Dash looked at her belly with surprise, and then to Twilight, “Twilight, what did you just do?”

Twilight only smirked as Spike rolled an entire cart full of deserts into the room. She then levitated a big slice of double-fudge cake into Rainbow’s mouth. Dash tried to resist at first, but her body seemed to work on auto-pilot once the delicious chocolate hit her tongue. She opened her mouth wide and soon swallowed the entire slice.

“We gotta keep that big belly nice and full. How else are we going to keep expanding your figure?”

“Twilight, are you seri-?!” Rainbow’s protest was cut off as Twilight shoved more cake into her mouth, which Dash had no choice but to chew and swallow, “You’ve been doing this all along?”

Twilight nodded as she forcefed Rainbow yet another slice of calorie-filled cake, “That’s right. It was just a professional experiment at first. But I slowly began to realize, I like you big. The larger you became, the more attracted to you I was. I can’t just let you destroy these amazing curves you’ve developed.”

Meanwhile, Spike had climbed on top of Rainbow Dash’s massive gut and was rubbing his hands all over her squishy flesh. He eagerly rubbed and pushed against her belly, watching in awe at how far he could sink in. “I’m sorry, Dash. But you’re just so awesome this way. So massive and plush.”

Rainbow blushed slightly as more cake was shoved into her maw. She was barely given enough time to protest further before the entirety of the cake had been stuffed into her stomach.

“Twilight, please...stop this...I won’t be able to move if I get much bigger.”

“You let me worry about that,” Twilight responded, “I’ll take care of everything.”

Twilight then levitated a large pie over, one of the dozens that Spike had recently baked. She decided to feed Dash by hoof this time, as she needed her magic for something else. During the magic expo, she managed to look over some very interesting research in partially mimicking the Changeling ability to hypnotize. There was no telling if it would work, but now was the best time to test it out.

“Listen carefully to my voice, Rainbow,” Twilight ordered in a very calm but firm voice as she looked deeply into Rainbow Dash’s eyes.

“C-Carefully…” Rainbow Dash replied, not being able to look away.

“You love food. You love being the biggest mare you can be,” Twilight suggest as she helped push the last of the first pie into her friend’s mouth.

“Love food...love being..b..n-no. I-I won’t let you do th-” Dash was cut off by a piece of the second pie being shoved past her lips.

“Shhh. Just let yourself go,” Twilight suggested. “It’s not like you could lose this weight anyway. Just look how big you are,” Twilight smiled as she slowly ran a hoof over the vast curvature of Rainbow’s towering belly. “There’s no going back now.”

“No going back…” Rainbow repeated as she accepted another slice of pie.

“You’re going to eat everything we give you, and you’ll enjoy watching yourself grow bigger every single day.”

“Enjoy...but...I don’t..wanna..” Rainbow Dash continued her attempts to resist, but Twilight’s spell continued to fog her mind. She tried to make herself focus on workouts, being athletic, losing weight. However, her mind kept drifting to how delicious all this sugary food was and how much she’d enjoyed getting to be so lazy. She had to get out of here soon or else she’d break. Unfortunately, any of her attempts to roll over were easily pushed back by Twilight. All she accomplished was making her belly wobble and jiggle like an ocean of jello, which just encouraged Twilight further.

“How much room does she have, Spike?” Twilight asked.

Spike gave Rainbow’s belly a good squeeze, feeling around for how taut it was. “Still super squishy!”

Twilight nodded, “Get the next wave ready,” she then turned back to Rainbow Dash,“Just let this part of you do all the thinking,” she gave Rainbow’s belly a light slap for emphasis, her hoof nearly bouncing off as Dash’s heavy blue gut rippled in waves on impact.

Spike returned with a cart of desserts packed with even more calories than the previous one. It contained upwards of 50 brownies filled with an obscene amount of chocolate chunks, nearly 3 dozen donuts with various fatty fillings, and the mother of all cakes that was lathered with dripping hot fudge.

“T-There’s no way I can eat all that,” Rainbow Dash mumbled, being temporarily let loose from Twilight’s intense hypnosis, “And I’m going to turn into a whale if you keep stuffing me at this rate.”

“Almost anything is possible with enough magic, Rainbow.” Twilight replied as Spike climbed up and forced the first of many brownies into Dash’s mouth, “As for you becoming a whale, that’s the whole idea~”

Twilight took alternating turns with Spike on stuffing Rainbow with brownies. All the while she began working her hypnosis spell again, “Just admit it, Dash. Deep down you enjoy this. You love to eat.”

“Love...to..eat,” Dash’s words were interrupted and distorted by all the chewing she was forced to do.

Twilight smirked as an audible gurgle came from Rainbow’s belly. It seemed her gut was already starting to process the new calories. However, a few deep pokes suggested that the massive mare still had plenty capacity for more. Looking back at the cart Twilight could see that Rainbow was already consuming her eleventh brownie. “Doesn’t it feel so good, Rainbow? All you have to do is lie back and let us stuff your big blue belly.”

“B-big...blue..belly…” Came the distant response.

“You won’t be the fastest mare in Equestria anymore, but you can certainly be the biggest.”

“B-biggest..”

Soon 20 brownies eaten became 30, then 40, and within impressive time the last had disappeared down Rainbow’s maw. The stuffed mare’s protests became less frequent throughout the process, and she was almost silently accepting it all as Twilight and Spike begin stuffing her with apple fritters next.

“S-So good...mmmm..so much,” Rainbow Dash began idly rubbing what small portion of her belly she could reach with her fattened and heavy hooves. The bliss of all this delicious food was clouding out previous resistance, and she found herself becoming more tired as her belly filled. “Feel..full..”

“Don’t worry, Rainbow. You still have some room, and you’re almost there,” Twilight nodded to Spike to ready the cake as Dash swallowed the last apple fritter. “All you’ve gotta do is eat this cake, then you can sleep and digest all those calories. Sound good?”

Rainbow Dash nodded, lazily opening her maw for the first slice of cake. It was clearly the most sugary selection of the night. All the chocolate and hot fudge hitting her tongue was almost enough to overload her taste buds completely. The first slice was quickly followed by a second. A small part of Rainbow’s mind shouted for her to stop this, but she no longer had the energy or the care to do so. Twilight was right, it was so much easier to sit back and enjoy this.

Twilight shoved the third slice into Rainbow’s mouth, noticing that for the first time tonight Dash’s belly was starting to rise. It was pretty impressive how much food Rainbow could consume before swelling. Her stomach capacity was likely already the greatest in Equestria.

“Now, Rainbow, I know you’ll probably fall asleep soon so there’s something I need you to remember. When you wake up, you’ll forget that I was behind any of this. You’ll remember that you did this to yourself. You’ll love your new size and won’t resist growing even larger. Got all that?”

Rainbow nodded blissfully while continuing to accept every slice of cake being pushed on her. It was at this point Twilight decided to step back and let Spike do all the feeding, meanwhile, she was free to rub and message Dash’s gut. It was now emitting deep and loud gurgles, already going into overtime to digest the massive load of food given to it. Twilight couldn’t even begin to fathom how many calories were currently in this belly. Twenty thousand? Thirty thousand? More? In any case, it would certainly result in an even bigger Rainbow Dash by morning.

Five slices. Six slices. Seven slices. Rainbow Dash could barely keep count as Spike forced bite after bite upon her. Even as she felt her belly stretching beyond normal capacity she couldn’t stop. She found herself feeling even more tired, her body wanting to just pass out so it could digest all this food. The moment she swallowed the final piece of cake she laid her head back and drifted off into a deep sleep.

“Wow, what a night. I can’t believe she really ate it all,” Spike remarked.

“This is nothing. Just wait until a month or two from now. I don’t think we’ve seen the limit of her gluttony yet,” Twilight sighed contently as she listened to the regular gurgling of Rainbow’s belly. Thanks to Twilight’s magic, Dash’s body was already hard at work digesting the sugary treats and sending the calories all over her body. By sunrise, those calories will have turned into several pounds of new fat deposited in various parts. Twilight amused herself by trying to guess what part of Rainbow’s body would grow the most. How many inches would add to her waistline? How much wider would her flank be? So much growth, and still so much to come.

“Let’s give her some time to rest. Be sure to wake up early tomorrow though, I want to have a good follow-up breakfast waiting. Just in case tonight wasn’t enough to push her all the way.”

Twilight decided to sleep next to Rainbow that night. She fell asleep to the pleasant sounds of Dash’s belly working overtime to expand her to even greater sizes. Rainbow Dash would awake not only as a larger mare, but one thoroughly hypnotized to love and enjoy the process of gaining weight.

Rainbow Dash’s eyes slowly fluttered open as sun shined through the window. The first thing that greeted her was the sight of the massive blue dome which comprised her belly. It totally obscured any view of her lower body. It was no longer painfully stuffed as it was last night but still felt a bit heavier in its own right. Rainbow reached out and began to rub the sides of her gut, feeling a strange surge of arousal as the fatty flesh squished beneath her hooves. The jello-like flesh allowed her hooves to sink in impressively far. She would have just been content to lay there for awhile, but motivation to move soon came to her. A wonderful smell moved in from the kitchen, one which caused her stomach to give a very aggressive growl. Rainbow began trying to roll herself over but struggled to do so. Her massive middle weighed her down like an anchor and jiggled endlessly as she rocked back and forth. Eventually, she managed to get on to her side, and then rolled on to the floor. She managed to get all four hooves on the ground, but only barely. Walking would be even more difficult. She was forced to spread her legs as wide as possible when she attempted to waddle for the kitchen. Even still, she could feel her belly dragging against the cold floor. She felt another surge of arousal. This state of near-immobility should have panicked her but yet she felt a perverse excitement about it. She huffed and puffed as she dragged her body across the room one very small bit at a time. It took her the better part of ten minutes to force herself into the kitchen.

In the kitchen, she saw Twilight and Spike hard at work preparing a massive buffet of a breakfast. Pancakes, french toast, waffles, cinnamon rolls, and several types of breakfast pastries were all being laid out. Twilight and Spike had modest plates with modest meals. However, on the other side of the table was a growing stack of food big enough to feed an entire house of ponies and then some. In front of that enticing buffet were a set of three full-sized chairs tied together. These chairs were draped with a ribbon that had “Rainbow Dash” written in big letters.

“Good morning, Rainbow Dash.” Twilight greeted with a giggle, “Well, almost afternoon now. Don’t sweat it though, you had a long night. Ready for some breakfast?”

Rainbow Dash nodded with a dopey smile on her face. She drug herself over to the table before attempting to sit down on the improvised multi-chair. The furniture groaned heavily as Rainbow’s obscenely large plot cheeks began to squish out all over them. Her massive rump was so big that it slightly hung off the sides of this extra-large seat. Meanwhile, she was forced to support her massive gut upon the table. It was at this point she realized there was no way to reach the food on her own. She was simply too large for her hooves to reach around her belly.

“Need some help?” Twilight and Spike approached her side with eager smiles. Rainbow Dash couldn’t even finish nodding before Twilight started using magic to feed her the first of the waffles. She was put into an immediate state of bliss from just the first bite. Her feeders had layered the waffles with obscene amounts of syrup and butter. The overwhelming sweetness made the food even more irresistible to her, in addition to promising more calories. She was on to her second and then her third waffle before she even knew it. The opening of her mouth and subsequent chewing of food was a nearly automatic process. By the fifth waffle, there was a small voice in her head which suggested to her she had enough. However, this idea was immediately shoved out of the way by a much more powerful urge to continue eating. She couldn’t stop until her belly was entirely full. Besides, it would be rude to not eat everything Twilight and Spike prepared for her. Any remnants of resistance quickly faded as she resolved to lay back and let her friends stuff her with the entire buffet.

Twilight noticed the waffles were nearly gone and began readying the pancakes. She emptied an entire bottle of syrup on to them in preparation. Meanwhile, Spike began the ambitious task of climbing on the table and then up Rainbow’s belly. Twilight giggled at the sight, marveling at how incredibly small her assistant was in comparison to the massive blue blob spilling out over much of the table. Spike eventually made it and laid himself out just in front of Dash’s chest. He gently grabbed hold of Rainbow’s fat and eagerly sunk his hands into the excess flesh.

“You’re so soft and bouncy, Rainbow. I could use your belly like a water bed.”

“Well if you keep helping Twilight make all that delicious food I suppose I could let you,” Dash gave a wide smile as Twilight levitated the second plate of pancakes over to Spike. The two then began taking turns shoving one pancake into Rainbow’s mouth after another, with every bite pushing her further into gluttony. She had a hard time even remembering why she used to be so obsessed with exercise. Why not just stay inside to enjoy all this amazing food and relax?

Twilight took a small break midway through the feeding session to admire Rainbow’s flank and her cutie-mark in particular. Her signature cloud and lightning bolt stretched heavily across the side of her rump. It was undoubtedly large enough to be spotted from many feet away. Twilight reached a hoof out and began to gently rub the side of her friend’s plot. Just the cloud of Dash’s cutie mark was bigger than Twilight’s hoof, and her face as well. Just for the fun of it, she decided to turn around and place her own cutie-mark right up against Rainbow Dash’s. Sure enough, her friend’s was big enough that Twilight’s own symbol could fit inside of it. Ironic that a cutie-mark which represented speed was now being stretched across one of Equestria’s fattest backsides.

“Hey, guys. I’m getting a little thirsty, got any milk?” Rainbow Dash asked as the pancakes were finally depleted.

“Sure do!” Twilight smiled as she levitated an entire keg of milk over and began pouring it into Rainbow’s mouth. Rainbow began eagerly drinking the thick liquid down, and her belly started to expand slightly as her capacity started to be stretched once again.

Gulp...Gulp…Gulp..

The blue mass of her middle stretched out even further, now reaching all but the farthest edges of the table. Both the table and the chairs beneath Rainbow were now creaking from the weight of the mare above them.

“Mmmhh...so full…” Rainbow panted as the milk jug was finally withdrawn. She began gently rubbing her belly as it gurgled with the contents inside.

“Don’t give up yet, Rainbow. There’s still little more to go.” Twilight gave her an encouraging smile as she readied two large plates of french toast.

Rainbow Dash bit her lip, “Well...I suppose I could stretch a little more.”

“That’s the spirit,” Twilight made sure to hand the second plate off to her accomplice as they continued their work. It probably wasn’t necessary to rush things, but Twilight was eager to pump as many calories into Rainbow Dash as possible. She knew if she played her cards right she could get Rainbow to the point of immobility by tomorrow or even the end of the day.

One slice. Two slices. Three slices. Four slices. Rainbow Dash couldn’t even keep up with as fast as Twilight and Spike fed her. She only barely had time to chew one piece before another was pushed on her. She could feel her belly continuing to stretch, and despite having just woken up not long ago she was starting to feel drowsy again. It was likely her body trying to force her to sleep so it could digest the incredible amount of food she consumed. Her feeders realized she was slowing down, so both began actively rubbing her belly to encourage her the rest of the way. To her own surprise, she managed to finish every bite. However, this was just before the table and chairs both gave way. Thankfully, Twilight was able to shield herself from any flying pieces. Rainbow was naturally fine, as her plot acted as two giant bags of cushion. Meanwhile Spike barely felt anything other than some extra jiggling from Dash’s belly.

“Whoops...sorry, Twilight. I’ve been breaking a lot of furniture lately,” Dash blushed heavily as she looked at the devastation.

“It’s alright, Rainbow. I should be more prepared when taking care of a mare your size. I’ll order replacements,” Twilight went to work sweeping up the pieces as she spoke.

Rainbow’s belly gurgled more aggressively, and she could even feel the added weight from her massive breakfast, “I’m going to be putting on some more pounds from this, aren’t I?”

“Ooooh yeah. You might not even be able to move when you wake up from your next nap.”

There was a small moment of clarity in Dash’s mind that railed against this, but she instinctively pushed the doubt aside once again.

“No, this is okay.” Even if she wasn’t able to move, she knew Twilight and her other friends would take care of her. Plus, It wasn’t like she could do anything about it even if she wanted to. She was barely able to walk to the kitchen this morning. Trying to exercise was a lost cause. All she really wanted to do was let herself fall asleep so she could process all this food and relieve her burdened stomach. In a few more moments she had drifted off into deep slumber once again.

A few months had passed since that day. A few more sessions of stuffing and hypnotism had left Rainbow Dash immobile and enjoying the fact. No longer able to walk, she spent her days being stuffed silly by Twilight Sparkle and Spike. Whenever she wasn’t eating, she was usually being washed or being played with by her caretakers. The two weren’t always there of course, which is why they left Rainbow Dash with access to endless amounts of Daring Do books, comics, and other forms of entertainment that didn’t require movement.

During the first weeks Rainbow was kept on the very same couch she first lost her mobility on. However, by the end of the first month, she became so large the couch snapped. She was then moved to a reinforced bed, and by the end of the second month, even that was starting to strain.

Twilight and Applejack had just finished putting together the pieces for Rainbow Dash’s third bed when they decided to take a break and go check on her.

“How do ya think the others are doing?” Applejack asked, “I bet they have their hooves full.”

Twilight giggled, “I don’t doubt it. I really appreciate you all pitching in to help.”

Applejack waved a hoof, “Ah, it’s nothing. It’s still hard to believe how massive she’s gotten though. I don’t know if there’s ever been a pony her size in history. How much does she even weigh now?”

“Well over a thousand pounds. I don’t know if she’s the biggest pony Equestria’s ever seen, but she will be soon at this rate.”

The two pushed into a large washroom that had been prepared specifically for Rainbow Dash. Her massive form was currently occupying a custom-made bathtub which was as large as a pool. Fluttershy, Pinkie Pie, and Rarity were hard at work trying to clean her. There was a lot of her to clean, however. Rainbow Dash smiled awkwardly as she felt her friends grabbing and rubbing the various parts of her fat body.

“H-Hey there, you two,” Rainbow Dash greeted, her voice heavily deepened by all the fat on her neck.

“Hey there, Rainbow,” Twilight responded with a smirk, eyeing up her friend’s form. Rainbow’s giant dome of a belly could easily substitute a king-sized bed. Twilight had spent many nights sleeping soundly on her friend’s massive gut, listening as it churned away digesting tens of thousands of calories that would make Rainbow Dash even larger. Her belly button was practically a small cavern. It was so large and deep one could stick their entire hoof in, or their head if they were brave enough. Further down was the absolute marvel of her hips and flank. Her hips were so wide that she had to be forcibly shoved even through double-doors. Her massive plot cheeks were positively obscene in their size and shape. Each massive boulder-sized sphere of lard was big enough for one pony to rest on. Her cutie marks were over five times their normal size, large enough to be seen from a great distance away. Twilight realized that the old Rainbow Dash would have been able to sleep comfortably on a cutie mark that size. It really hit home just how much of a whale she’d become. Looking even further down, Dash’s thighs were so massive and thick that her actual hooves looked like tiny stubs which barely stuck out from all the fat.

“How ya feeling, Rainbow?” Applejack asked, shaking out of her daze before Twilight could.

“Bigger than ever. I really appreciate you all helping me out until Twilight can find a shrinking spell.”

Twilight chuckled lightly, “It’ll still be a little while on that. But don’t you worry, I haven’t given up. In the meanwhile, I’ve found something new for you to do. Apparently, Photo Finish is interested in taking some pictures of you.”

“What, why?”

Twilight shrugged, “Some ponies like big mares, and you’re probably the biggest. I doubt most ponies would even believe your size unless they saw it.”

Rainbow Dash’s puffy cheeks turned a shade of red, “W-Well, okay. Don’t suppose I have anything better to do.”

“Great, once you’re washed up and we can start getting it all ready. You’re going to be quite famous after today. Even if it’s for different reasons than before.”

“I hope they have a reaaaaaally big camera,” Pinkie teased, “I tried to take one of Rainbow a few weeks ago and the entire picture was just a bunch of blue filling the frame.”

Meanwhile, Fluttershy began washing Rainbow Dash’s flank. She tried to not make it look like groping, but the others could tell how she was intentionally grabbing and rubbing a small part of Rainbow’s right flank cheek. She had to ask Twilight for magical assistance when moving on to the back of Rainbow’s legs, as Dash’s plot easily weighed a couple hundred pounds on its own.

“How're your plans for designing an outfit coming along, Rarity?” Twilight asked as both unicorns used their magic to hold up Rainbow Dash’s backside so the others could wash underneath.

“It’s the most difficult fashion undertaking in history. Particularly since her measurements are continuously increasing, but I think I’m close to a breakthrough. I’ve really enjoyed this unique challenge.”

“I look forward to seeing what you come up with,” Twilight gave a slight smile. She had to admit it would be pretty enticing to see all of Rainbow Dash’s fat being squished into a piece of clothing, even if she’d outgrow said clothing in just a week or two at most.

After the washing was concluded the group, through much effort, moved Rainbow Dash into a large makeshift studio which was going to be used for the photoshoot. It took the better part of an hour to get their massive friend in position. However, they managed to finish just in time for Photo Finish and her crew to arrive. She was absolutely awestruck upon entering the room.

“Mien goodness...you told me she had gotten even larger...but I never expected to this extreme.”

“I hope that won’t be a problem,” Twilight mused.

“Not at all!” Photo Finish turned to her crew members, “Ready ze wide angle lenses!”

The underlings quickly went to work setting up cameras around the room. It was already clear that they wouldn’t be able to get all of Rainbow Dash in frame no matter how they positioned, so the strategy was to capture her one area at a time. First, they had her rolled over on her back so they could take shots of her mountainous belly. It reached up over halfway to the ceiling and required a pegasus to fly up and capture downward shots. Said pegasus gave out a light squeak of fear when she nearly fell into Rainbow’s cavernous belly button, which was probably large enough to hold her.

“Now for her flank, get her rolled over!” Everyone in the room worked to get Rainbow Dash on to her belly. The immobile mare jiggled almost non-stop as her belly squished out beneath her like an obscenely large balloon.

“Give us a shake!” Photo Finish ordered next.

Rainbow Dash bit her lip and mustered what control she had left in her lower body to start clapping her boulder-sized plot cheeks together. Extremely lewd slapping sounds filled the room as the massive fleshy spheres slapped against one another. “Like this?” Rainbow Dash blushed heavily at showing herself off in such a manner.

“That’s perfect, keep it up!”

Twilight flapped her wings and flew up in front of Rainbow Dash’s face, “Having fun, Dash?”

Rainbow gave a slight nod, “It’s really nice having all this attention. I guess I’m going to be Equestria’s most famous freak show after this huh?”

“Maybe, but you’re the best-looking freak show I’ve ever seen.”

“Hey, Twi. This is kinda a lot of work, think I could get some food after this?”

“Oh, Dash. Have I ever let your stomach go empty?” The two giggled together. Twilight couldn’t have been more satisfied with this outcome. This experiment had definitely been a resounding success.

No Pain, No Gain

No Pain, No Gain

Twilight made a point of awaking early the next morning to observe the effects of the previous day. She walked very cautiously and quietly down the stairs to avoid waking up either Rainbow Dash or Spike. She found Rainbow Dash on the couch where she left her last night. Dash was sleeping soundly, no doubt she needed it to process the sheer amount of food she consumed yesterday. Between Rainbow's birthday party and the evening long gorging she participated in it was impossible for Twilight to even begin calculating the sheer amount of calories that must of been ingested. Tank was sleeping next to her just as soundly, snuggled comfortably against his owner's soft middle. He had been delivered by Fluttershy later the previous evening.

Twilight carefully moved in closer to get a good look. The changes to Rainbow Dash's body were slight, slight enough that most ponies and maybe even Dash herself wouldn't be able to notice. However, to Twilight who had been keeping careful note of Dash's figure since the start of the experiment, almost any change could be detected. Rainbow Dash's belly was squished out beneath her like a water balloon. A few inches if not more had definitely been added to her waistline. Her flank had absorbed further weight as well. Her cutie marks were now over twice their normal size as they stretched across her rounded plot cheeks. It seemed that Dash's body slightly preferred carrying weight in the rear over the center. There was added fat to be found all over though. Her back legs were becoming thick enough to start rubbing together on a regular basis. Twilight thought she could even see the early signs of a triple chin under Dash's face.

Twilight was already putting her plan for the day together when Spike walked into the living room. She nodded to him to meet her in the kitchen before trotting in. "Alright,Spike, I've got an interesting job for you this morning. You're going to be my assistant chef. Rainbow Dash is going to start her new exercise routine today and I want us to make sure it goes as smoothly as possible. We'll have to prepare some good meals for our guest, and I've also come up with a recipe for some shakes that will definitely help with Dash's workout."

Spike took a good look at the recipe list that Twilight promptly levitated over to him. It was filled with thing such as chocolate, peanut butter, candy, and other assorted sweets. "Uhhh...Twilight, I'm no weight loss expert or anything..but isn't this recipe a little too calorie heavy for a pony trying to get thin?"

Twilight smiled and shook her head,"I've come up with a new spell that will instantly turn the food in a pony's stomach into energy. So all the calories in that shake will only go to helping Rainbow Dash exercise with no worries about adding on pounds," she didn't like lying to Spike at all. However, telling him the true intention of all this would be disastrous.

"Ohhh...I get it. That's a pretty good idea,Twilight. I'll start getting those ingredients together right away," With that Spike got to work assembling various food items. While he did that Twilight focused on preparing a hearty breakfast. Cooking up a wide assortment of hay bacon strips,eggs, and well-buttered toast. Once it was finished she divided the meal into three platters. A few smaller ones for herself and Spike, leaving the rest for Rainbow Dash.

Rainbow Dash awoke to the pleasant smell of hay bacon strips filling her nose. As she opened her eyes she saw both Twilight and Spike in their own spots of the room eating breakfast. She could feel Tank sleeping next to her, but had to crane her neck in order to see him. Just in front of her on a table was a food platter of her own. The plate was filled with far more than she should probably eat but was very tempting none the less.

"Good morning, Rainbow Dash," greeted Twilight, "You better eat up. You've got a hard day of exercise ahead."

"Thanks,Twi," Rainbow Dash replied, "But this is a little bit heavier of a breakfast than I had in mind."

"Oh, don't worry about that. I have a new spell that will turn all the food in your belly to instant energy. It'll work wonders for your exercise. Just eat as much of that as you can and trust me."

Rainbow Dash shrugged as she thought about the idea. There was no reason not to trust Twilight. Plus it would be an excuse to gorge out on the awesome looking meal in front of her. With some effort she managed to shift herself into sitting position, grabbing hold of Tank and moving him safely aside at the same time. She then had to reach around the large doughy sphere that comprised her belly in order to reach her food. Once she did there was no stopping here. The first taste of hay bacon strips hitting her tongue sent her into an eating frenzy. Not long after the strips were finished she was practically shoveling multiple servings of eggs into her mouth at once. After that only the toast remained, but not for long. Despite their being several slices it was all gone in just a few minutes. She laid back and gave her rounded belly a satisfied tap, causing it to ripple. It was only now that she noticed Twilight and Spike looking at her. Spike in particular seemed shocked. "What? You said eat as much as I can. Now let's get outside. I hope this spell is worth it, Twi."

With that Rainbow Dash rolled off the couch and got to her hooves. It was a good thing she was taking her workout into overdrive. As just simply getting up and moving around seemed to be becoming a slight chore. Something had to be done to help combat her growing laziness. Although she was confident that her new found problems would start going away after today.

Twilight followed Rainbow Dash outside, taking a moment to note the shrinking clearance between Dash's widened hips and the door-frame. Once outside Rainbow seemed eager as ever to get started.

"Alright,Twi. I think I'm going to start with a good jog. Go ahead and hit me with that energy spell."

Twilight nodded as she charged her horn and casted her magic. In reality it was simply the same spells she had been using on Rainbow Dash for the past month. Hopefully she'd be tricked into thinking the advertised effect was happening instead. "So Dash, how do you feel? Did it work?"

Rainbow Dash paused thoughtfully, "Well, my stomach feels lighter. Maybe it did?"

"Hmm. Perhaps it'll just take time before the energy from the food kicks in. Go ahead and start running. I'll be right behind you."

On cue Rainbow Dash took off running. It was closer to simple jogging, but that was probably the fastest Rainbow could now manage with all the extra bulk. Twilight followed close behind and soon became very satisfied with her new job for the day. The jogging caused the fat on Rainbow Dash's figure to move dramatically. Her large dome-shaped belly swayed back and forth, part of it occasionally smacking against her thighs. Her thick back legs were so close to rubbing up against each other that Dash was constantly trying to spread them farther apart. The most hypnotizing part of the display was none other than her flank. The two over-sized cheeks that comprised her plot were bouncing and shaking without regret after each step their owner took. That huge jiggling plot seemed to demand the attention of anypony who glanced it. Twilight happily gave in to the demand. So much that she often had to remind herself to keep running and not fall behind.

The display was short but sweet as Dash soon collapsed on the ground and began panting. The two of them had only been jogging for a couple of minutes and were still within short range of the library. Twilight saw this as the perfect chance to begin her plans for the day. "Just take a quick break,Rainbow. I'm going to go back to library and come back with something that should help you keep excercising."

Rainbow Dash merely gave an exhausted nod as Twilight quickly trotted off. Soon she returned holding up an "energy shake" with magic. She set it down near an exhausted Rainbow Dash who greedily chugged it down. Afterwards she casted the usual spell. "Well, Rainbow, feeling energized again?"

Dash shook her head,"Not really, still feeling a bit tired."

"Hmm. I may need to increase the reaction time of this spell a little, but it'll kick in soon enough. Best thing you can do is get back out there and push yourself until it starts working."

Rainbow Dash slowly picked herself and began jogging at a light pace again, with Twilight right behind her. As they went through the town Dash's new figure was far from unnoticed. Nearly everypony they passed by stopped what they were doing atleast briefly to look at Rainbow. Some seemed disgusted, but most where either shocked or enticed by the sight. There was quite a few sets of wandering eyes looking over the more jiggle prone parts of Dash's body. Her swaying belly and bouncing plot competed for most of the attention.

By the time they reached Sugarcube Corner Dash was out of steam again. She collapsed on the ground panting heavier than before, "Phew....I don't think energy spells....will help at this point. I'm done...for today."

"That's alright, Rainbow. You did pretty good today.", Twilight knew that was far from the truth. In fact, Rainbow Dash had only gotten a limited amount of real exercise done. However, it was best to make her think that her current workout regime was going to help her lose weight. It might be enough to distract her from her continuing gain for awhile. "I think you deserve an award. How about we go inside and have Pinkie whip up some nice snacks?"

Some energy returned to Dash at the mention of food. The prospect of snacks now motivating her more than any workout could. "That sounds like a great idea. With as hard as I worked out today I don't have to worry at all about what I eat."

With that the two entered Sugarcube Corner and were quickly greeted by Pinkie Pie. "Hi there Twilight, Rainbow Dash. I'm glad you stopped by. I need some ponies to taste test for some new recipes!"

"We'd be happy to, Pinkie.", Twilight replied, "We had actually come in here for some snacks anyways. Rainbow Dash has been having a hard workout today and she's really hungry."

Pinkie Pie darted out of the room and into the kitchen before returning with an assortment of different flavored mini-cakes. Each brightly colored and indicating their unique combination of flavor. "There's plenty to choose from; Lemon Marble, Chocolate Cheery, Butter Banana...."

As Pinkie Pie continued listing off the flavors Rainbow Dash sat down and began to eye the assorted cakes with more and more temptation. Before Pinkie had even finished listing them all Dash dove in and began scooping out slices from multiple different cakes. Shoveling down the sugary deliciousness with reckless abandon. Twilight watched with awe. Every passing day her new spells began to demonstrate more long-term effects. Dash hardly seemed aware of how much she was eating anymore. It was if gluttony was becoming instinct for her.

Within almost no time at all the once vast assortment of baked goods was gone. It was all packed away tightly within Rainbow Dash's belly. She leaned back in satisfaction as Pinkie Pie looked on an amazement. "Wow, Rainbow. Those must of been good. What did you think?"

"Those cakes were awesome. Just one question though, got anything I can take to go?"