It is by Pegacorn Ondacob.
It was a beautiful day in Ponyville. The sun was shining, the birds were singing, and everypony was out having fun in the nice weather. It was all thanks to the most dependable pegasus on the weather team: Rainbow Dash. The pony in question was at the moment resting on what to her might very well be the most comfortable cloud in all of Equestria after a hard day of handling the weather like she normally did. She had been resting for awhile when she just thought about another appointment that she had to keep. Getting up and stretching her wings, she flew low over the busy town. Looking down she spotted Scootaloo who gave her idol a friendly wave. Smiling, Dash waved back and went on her way to her destination. It didn’t take long for her to reach her long time friend’s house. Rainbow Dash landed on the front step of Fluttershy’s moss grown and knocked on the door. A short while later a familiar yellow pegasus answered the door and smiled sweetly at her.
The two of them had been friends since they were fillies. But whereas Rainbow Dash continued to remain in Cloudsdale following the events of the sonic rainboom, Fluttershy chose to remain on the ground and build her home just beyond the outskirts of the Everfree Forest where all the animals lived. Fluttershy had garnered a reputation among her friends as someone who was good with animals and taking care of injured or sick woodland creatures. She despite herself also proved herself capable in foalsitting as she had when she was put in charge of the Cutiemark Crusaders when Rarity was unable to look after them. It was a lifestyle that Rainbow Dash could never imagine having as it was too slow paced for her. Yet despite the two pegasus’ vastly different lifestyles and interests, the two remained very close friends, which is why Rainbow Dash didn’t think twice when Fluttershy requested that she join her on this day.
“Oh, Rainbow Dash! Thank you so much for coming! Please come in,” said the pink haired pony.
“Dun mind if I do, Fluttershy,” said the blue pony as she stepped over the threshold. “I hope I’m not too late.”
“Oh no, Dash. I may have said ‘some time after noon’ but I didn’t have a specific time in mind.”
“Good, cause I took a little nap after getting the sky cleared early.”
“Oh!” said Fluttershy, “Well in that case you must be thirsty!”
“Come to think of it, I am a little parched.”
“You wait right there! I’ll be right back.”
Fluttershy disappeared for a moment and reappeared shortly after holding a silver tray in her mouth. On the tray was a single glass full of ice and a transparent yellow liquid, topped with a flexible straw. She placed the tray on a nearby table and Rainbow Dash at once approached the table and sucked on the small plastic tube, drawing liquid into her mouth.
“Mmmm! This is tasty and refreshing! What is it?”
“It’s a sports drink that Pinkie Pie came up with. It’s supposed to help rehydrate the body faster than water can alone. She calls it ‘Gummyade.’ ”
“Well remind me to thank her later on,” said the blue Pegasus as she drank some more through the straw. “So what did you call me here over for? It is something having to do with one of your small critters?”
“No. I wanted you to come over because you’re my best friend and I wanted to talk to you about something that’s been on my mind for awhile. Foalsitting the Cutiemark Crusaders got me thinking. Looking after animals is nice and everything, but eventually I want to be a mommy. I want to have a baby of my own to raise and nuture and pamper.”
“Well I’m sure you’ll make a great mommy.”
“Thank you, Rainbow Dash. I’m really glad you say that. That means a lot to me coming from you.”
The blue pegasus took another sip of her drink.
“Do you know the lullaby I used to try to put the Cutiemark Crusaders to sleep?” asked Fluttershy.
“Not off the top of my head,” said Rainbow Dash.
Fluttershy cleared her throat and began to sing.
“Hush now, quiet now,
It's time to lay your sleepy head,
Hush now, quiet now,
It's time to go to bed,
Drifting off to sleep,
Leave exciting day behind you,
Drifting off to sleep,
Let the joy of daylight find you.”
As she sang, Rainbow Dash began to feel tired and light-headed. At first she thought she was more tired than she realized. Then she thought that maybe her friend’s lullaby was really that powerful. Finally her suspicion fell upon the glass of the unnaturally colored yellow liquid. Looking at it and smelling it, she turned to her friend. She wanted to say something, but Fluttershy continued to sing her song and soon Rainbow Dash collapsed on the spot, lost to the darkness.
Rainbow Dash regained consciousness sometime later, but still found herself in darkness. She started to stretch her limbs only to find that she couldn’t. She was restrained and could barely move her arms and legs which were strapped down. Immediately she called out to the darkness for help.
“Oh good. You’re awake. We can get started!” a familiar voice called out.
A light turned on to reveal everything. Rainbow Dash appeared to be strapped down to some sort of changing table by her legs, torso and arms. She was restrained in such a way that she could not move her wings at all. The room appeared to be some sort of nursery. The walls and carpet were decorated in pastels. There was a playpen, a crib, a closet, baby toys and other paraphernalia suitable for the youngest of foals. More disturbing than her being restrained in such a way was that none of the items seemed size appropriate for a foal. They seemed made for an adult pony. Fluttershy was in the doorway and looked at the restrained Pegasus with a smile on her face.
“Fluttershy, what’s going on here?” said the blue pony with more of a sense of irk than disturbance. “Why am I strapped down?”
“Well … remember earlier out how I said I wanted to be a mommy and have a baby of my very own?”
“I vaguely remember something like that before blacking out. Hey, wait a minute! What did you put in my drink? Did you drug me?”
“I did and I’m sorry. But it was necessary for you to cooperate. You see I’ve been going over a lot of options. At first I thought about giving birth to my own foal, but I don’t even have a boyfriend. Then I thought about adoption, but that’s full of complications and often a lot of red tape. Then I thought about us and how we’ve been friends longer than any of the other girls. That’s when I realized that you would be a perfect baby for me.”
Rainbow Dash just stared at Fluttershy for a bit and burst out laughing.
“Oh that’s rich, Fluttershy. Wanting me to be your baby. How did you come up with this prank? Did Pinkie Pie help you?”
Fluttershy tilted her head.
“Prank? Oh no, Rainbow Dash. I am being most sincere. And I guarantee that by day’s end, you will be calling me ‘mommy.’ ”
“Pfft! Like that’s going to happen.”
“Time will tell. Let’s get started.”
Fluttershy began by reaching for something that was in one of the compartments of the changing table. She presented a set of four bondage mitts that were covered in pink fleece so they looked like booties for newborns. Before Rainbow Dash could protest, Fluttershy was already working to secure the mitts on Dash’s hooves one by one.
“What are these for?” asked Rainbow Dash.
“So that you don’t mess with the next thing I’m going to put on you.”
Rainbow Dash raised an eyebrow at her friend. Fluttershy said nothing and continued to put the bondage mitts on her friend’s hooves until they were nice and snug. Once she was finished she pulled out what was clearly a thick yellow diaper that was made to fit an adult size but still decorated to look like one for a filly. She began to undo the diaper. Dash looked on with disgust.
“Oooooh no! You don’t plan to put that on me, do you?” said Dash.
“Not only will you wear it, but you will use it too.”
“Like Hell I will!”
Fluttershy pretended she didn’t hear that and proceeded to put the diaper on her friend. Rainbow Dash couldn’t exactly struggle much since the straps held her down. So it wasn’t long before the diaper was on her rear and secured in place. Dash stared in awe at the piece of cloth, plastic, tapes and absorbent material hugging her waist. She hasn’t worn of these since she was very young. The first filly among her peers to be potty trained, and here she was in diapers again. She looked down at it and noticed the pattern on the diaper.
“Pink butterflies?” asked Rainbow Dash.
“Yep. My cutiemark. That way anyone can look at your diaper and know right away who your mama is.”
“Look, Fluttershy. I don’t know what’d gotten into you, but I am NOT a little filly and you are NOT my mama.”
“Awww. A little grumpy, I see. Let me remove those straps.”
Fluttershy began to remove the straps one by one. Rainbow Dash began to stretch her limbs with each new liberated limb. She waited with bated breath as Fluttershy began to remove the strap holding her chest down. Finally there was nothing holding her down.
“I’m outta here!” exclaimed Rainbow Dash.
She sprang from the changing table with every intention of flying out of the room and out the front door. But she had barely gotten off the table when she fell down, crashing head first on the floor. Fluttershy helped her up and held the diapered pony in her arms.
“Are you okay, Dashy?” she asked.
“Ugh. I’m feeling kinda weak for some reason.”
“Silly filly. You know very well little that you’re not strong enough to fly. Not yet, at least. After all, you’re just a baby.”
“Oh yeah? Well I can still remove this diaper!”
Rainbow Dash shuffled out of Fluttershy’s grasp and tried to remove the diaper, but try as she might, between the loss of grip due to the mitts and her noticeable lack of strength, she was unable to do so. She sat on her padded duff, crossed her arms and gave a slight huff when she realized it was hopeless.
“Oh Dash, don’t be silly. You can’t leave. Not looking like that. What would people say? What would Scootaloo say? You simply aren’t strong enough right now.”
Rainbow Dash glared at Fluttershy. She knew very well she was at the yellow pegasus’ mercy.
“Okay, Fluttershy. What will it take to get this diaper off?”
“Humor me for the rest of the day. If you’re not happy by day’s end, you’ll be free to go.”
“That’s it? I just have to play baby with you for a day and I’m free to go?”
“Okay … I guess I can deal with that. What did you want to do first?”
Fluttershy gave a squeaky grin and sat down in front of Rainbow Dash.
“Pattycake!” exclaimed Fluttershy.
“Pattycake?” said the diapered pony.
“Pattycake!” said Fluttershy holding her hooves out in front of her.
Rainbow Dash sighed and put her hooves out in front of her. Fluttershy sang but Dash declined to join in, and only matched Fluttershy’s claps with her own.
“Pat a cake, pat a cake, baker’s colt,
Bake me a cake as fast as a bolt,
Pat it, and prick it, and mark it with a D,
And put it in the oven for Dashy and me!”
On that last part, Fluttershy gave one of her signature cheers.
“Yeah … that was really … something,” said Rainbow Dash.
Just then Rainbow Dash’s body was telling her something she didn’t want to hear, especially not as she was now. She wiggled her legs a bit.
“Uh, Fluttershy. I don’t know how to say this but … I … need go water the flowers.”
“Oh you don’t have to Dashy. I already watered my garden this morning.”
“No, what I mean is I need to go use the little filly’s room.”
“Oh! Well then by all means! You’re free to go.”
Rainbow Dash blinked.
“Really? Then in that case could you help me get this diaper off?”
“Oh no, no, no. You misunderstand. You’re free to go … in your diapers.”
Rainbow Dash was about to protest, but before she could she thought about what Fluttershy said earlier about her being free to go if she cooperated and simply huffed.
“I can hold it,” she Rainbow Dash.
“If you say so,” said Fluttershy.
The two of them spend the next half hour or so playing as any mother and daughter would. Fluttershy had put a lot of effort into the nursery room. There was a table with a pink tablecloth and a tea set. Rainbow Dash was not entirely keen on having a tea party with Fluttershy, but abided as best as she could. The closet was also filled with all manner of infantile clothing. Fluttershy had Rainbow Dash try one each outfit and model it for her much to the blue pony’s dismay.
“These dresses look adorable on you, Rainbow Dash.”
Rainbow Dash, who was currently wearing a pink frilly maid-like dress only huffed. Just then Fluttershy looked as if she had suddenly remembered something.
“Oh, I just remembered that I have to check on one of the animals in my care. I’ll be right back, baby,” said Fluttershy as she went out of the room
Fluttershy had left the door to the nursery open. Rainbow Dash was tempted to escape to the outside, but decided against it considering how she was dressed and had no way to change that. By now she realized that she could no longer hold in her bladder. She needed to relieve herself one way or the other. Looking and listening around to make sure Fluttershy was not around, she spread her legs, pulled up her dress, and finally let it all go in her diaper, giving a sigh of relief. When she was done, the pink butterflies on her yellow diaper had disappeared and her diaper was much warmer and softer. Curiosity got the better of her and she started to play with her wet diapers.
“Enjoying your diapers, I see.”
Rainbow Dash almost peed her diapers again when she heard that. She turned and saw that Fluttershy had returned and she hadn’t noticed.
“Er … no!” said the blue pony pushing her dress down. “I hate these things. Get them off!”
“I’ll tell you what. Just call me ‘mommy’ and I’ll change your diapers.”
Rainbow Dash considered the option but quickly put it out of her mind.
“I’ve been in worse situations. I don’t mind the diapers.”
She stopped for a moment and realized what she just said.
“Er … that’s not what I mean,” said the blue pegasus waving her hooves in front of her. “I meant that I would rather be in diapers than call you ‘mommy.’ ”
Suddenly Rainbow Dash’s stomach began to grumble.
“Looks like someone is hungry!” said the yellow pegasus, “Follow me. I’ll fix you up something.”
Fluttershy trotted out of the nursery and Rainbow Dash followed after. The diaper on her rear made a distinct crinkling noise as she walked. Rainbow Dash cringed at the feeling, but tolerated it for the moment if playing along meant her eventual freedom. Fluttershy went into the kitchen while Rainbow Dash remained in the dining room. There was a table, but no places to sit at it. Fluttershy came out soon after with a tray with a bowl filled with hot cereal and spoon and set the tray on the table.
“Oatmeal?” asked Rainbow Dash.
“Indeed,” said Fluttershy.
“I suppose I could go for some oatmeal.”
“Have a seat, please.”
“Where? There’s no place to sit.”
Fluttershy pointed to a piece of furniture that escaped Rainbow Dash’s attention when she first came into the room. It was a high chair, complete with built-in table and buckling belt to keep the occupant safe in it.
“There is no way I am sitting in that!” said Dash as she crossed her arms.
Fluttershy gave Rainbow Dash a look like that of a puppydog as a means of silently pleading with her. Rainbow Dash only shook her head from side to side in defiance. Then Fluttershy did something she had never done to her friend before. She gave her the stare. It was the look that always filled those she gave it to with dread. Rainbow Dash lowered her ears and backed away slowly. Without a word she got into the high chair. Once she was seated, Fluttershy returned to her normal disposition and came over and buckled the blue diapered pony in and closed the tray, effectively locking her into the chair. Once this was done she brought the bowl of oatmeal and spoon and placed it on the highchair tray.
“Oh! I almost forgot!” said Fluttershy.
She ran out for a bit and returned with a bib. Rainbow Dash was a bit tired of protesting, so she let Fluttershy put the bib on her without much of a fuss. Then Fluttershy took the spoon and put it the oatmeal.
“Now, Dashy. Are you going to be a good filly and let me feed you?”
Fluttershy gripped the handle of the spoon with her teeth and scooped up a helping of oatmeal. Smiling she brought it to Dash’s mouth. Rainbow Dash opened her mouth and allowed the spoon inside. Wrapping her lips around the spoon, she drew the food into her mouth while Fluttershy drew the spoon out. This process repeated over and over again until the bowl was empty. All the while nothing but thoughts of sheer and utter humiliation filled Rainbow Dash’s head as well as fears of what anyone might say if they saw her like this.
“There. All done,” said Fluttershy with pride. “Oh my! You spilled some. Good thing you have that bib!”
Fluttershy used the spoon to scoop up the excess oatmeal and feed it to Dash. Once she was done, Fluttershy removed the bowl and spoon and set them to one side.
“Now I imagine you’re thirsty, right?” said the yellow pony.
“I could use something to drink … as long as it’s not anymore of that Gummyade stuff.”
Fluttershy nodded and went into the kitchen and returned with a baby bottle.
“I should have seen this one coming,” said the blue pony.
Fluttershy held the bottle with her hoof up to her friend’s mouth. Rainbow Dash gave a sigh of utter defeat and wrapped her lips around the amber nipple and began to suckle. Her efforts resulted in a trickle of warm milk in her mouth. It seemed like an awfully lot of work just to drink some milk. But as she did so, something happened that she did not expect. The suckling action was calming her down. Soon the suckling motion became autonomous and Rainbow Dash drank to her heart’s content. Fluttershy seemed to notice this change as well and smiled widely. Once she was done, she removed the bottle, but Rainbow Dash was still making a suckling motion with her lips. Fluttershy responded by placing a pacifier on a pendant in Dash’s mouth which she took to quite well.
“Come on, my little filly,” said Fluttershy as she removed the tray and restraints from the high chair, and helped Rainbow Dash down.
After a nutritious meal, Fluttershy escorted Rainbow Dash back to the nursery. Fluttershy saw that Rainbow Dash was visibly beginning to break down, but knew it was a little premature to tell if her efforts were completely successful. For all she knew, the blue pony was merely playing along with the promise of freedom at the end of the day if she cooperated. Rainbow Dash was still suckling on her paci when she walked into the nursery, her rear crinkling behind her. She walked over to a nearby teddy bear and began to cuddle with it.
Fluttershy decided that now would be a good time for a story, so she reached for a book from a nearby bookshelf and went over to a nearby bean bag and called Rainbow Dash over to her. Rainbow Dash seemed quite disorientated but found her way next to Fluttershy and sat in the beanbag chair with her. Fluttershy opened the book and read aloud. The story itself was nothing terribly earth shattering. It was about a pony wishing to hold the world’s biggest tea party. But Fluttershy read the story as if she were the newly elected mayor of Ponyville reading her inaugural address. When she was done, she closed the book and turned to Dash.
“So, Dashy. What did you think of the story?”
Rainbow Dash spit out the pacifier which was attached via a pendant.
“Eh … it was okay. It’s no Harry Trotter and the Fillyosopher’s Stone, though.”
“I see. Then in that case maybe I should show you something else.”
Fluttershy got up and put the book away and returned with a photo album. She sat down next to the diapered pony and opened the album. The first photo was that of Fluttershy as a young filly, still living in Cloudsdale.
“Aww … how cute,” said Rainbow Dash.
Fluttershy turned the page which revealed photos of the other five ponies in their circle of friends as young fillies, including Rainbow Dash. The blue pony smiled and laughed at the sight. Then Fluttershy turned the page and Rainbow Dash’s laughter stopped. The first photo was of Cheerilee in a short dress, diaper and pacifier and holding a stuffed animal. She was clearly not a filly in this photo, but of adult age and posed provocatively for the camera. The next photo showed the mayor of Ponyville dressed similarly and then Carrot and Cup Cake also dressed in baby outfits. One by one Fluttershy turned the pages of the album to reveal more of the same: citizens of Ponyville turned into adult foals. Futher pages revealed intimate diapered photos of Lyra, BonBon, Spike, Braeburn, Big McIntosh, and sure enough Pinkie Pie, Rarity, Applejack and Twilight Sparkle too. When Rainbow Dash saw a photo of various members of The Wonderbolts in diapers, she jumped up and made a run for the door.
“Where are you going?” asked Fluttershy.
“Away from you!” said Rainbow Dash in disgust. “This is sick! Grown ponies in diapers? What did you do to them all?”
“Now Dashy, all these photos were taken with permission. These ponies and I consented to a little adult foal play and
each photo is a fond memory of it.”
“So why force this on me?”
“I told you. You’re going to be my baby.”
“Screw that! You think I am going to take this? You think I’m going to allow you to treat me like a baby just becau…?”
But before Rainbow Dash could finish, something happened that the blue pony never foresaw. She messed her diapers. She didn’t even feel it happening, nor was she given any time to react to it. It just happened. One moment she was talking and the next minute she was filling her diapers with excrement as it were as natural and automatic as breathing. All this paralyzed the blue pony with fear. When the deed was done, she reached behind her and patted her diapered rear, causing it to squish. Rainbow Dash realized that for reasons beyond her understanding, she had messed herself uncontrollably and it frightened her to the core. She began to cry.
“Aww … there, there,” said Fluttershy comforting the blue pegasus. “It’s okay. Want me to change your diapers?”
As much as she hated to admit it, she needed a good diaper change and nodded.
“Okay, but if you want me to change you, you need to call me ‘mommy’ and then ask me to change you.”
Rainbow Dash thought about this and what it would mean for her. She was in quite a predicament right now and the only way out was through the very person who put her into this mess. She had little choice in the matter. Prolonging the inevitable would only make it worse on her.
“I … I … I” began the scared blue pegasus.
“What’s that?” asked the yellow pegasus.
Rainbow Dash was beginning to feel really filthy, both internally and externally. She knew what she had to do.
“Mommy, I want you to change my diapees,” she said.
Did she really say “diapees” instead of “diapers?” Fluttershy smiled approvingly and escorted Dash to the changing table. It didn’t take any fancy instruction of what she was supposed to do. She laid down on the changing table and held her hooves up. Fluttershy swiftly undid the messy diaper, rolling it up and throwing it away. Then she started to clean up Dash with a series of moist towelettes. As she felt the baby wipes cleansing her, Rainbow Dash was put further at ease, as if each wipe was wiping away any doubt and fear in her mind. By the time she was completely cleaned, Rainbow Dash felt much better and more receptive. Fluttershy took some baby powder and spread is all over the blue pony’s nether regions. Finally Fluttershy unfolded a new diaper and placed it on Dash and secured it in place. The diaper sealed the deal. Everything up to this point had been in a effort to break the blue Pegasus known as Rainbow Dash, but the diaper made certain that she would stay broken. Rainbow Dash giggled and put her paci back in her mouth and patted her new diaper. Fluttershy giggled and picked Dash off the table and set her on the floor.
“How do you feel, baby?” asked Fluttershy.
“I feel wonderful, mommy!” exclaimed Rainbow Dash.
“Wonderful! I couldn’t have asked for a better filly. I love you, Dashy.”
“I love you too, mommy!”
As a teenage pony, Rainbow Dash was always so adventurous and apt to crashing into things. As a mentally regressed filly, she retained these traits, but now found herself answering to Fluttershy. Her best friend was now her mommy, and it made her happy to be a filly again with a mother who loved her. Fluttershy on the other hand got to experience the joys of being a parent through a filly made from her best friend who was now completely dependent on her. Caring for the regressed Rainbow Dash much to her surprise had brought Fluttershy more joy than any baby bunny, sick bird or animal in need of care had ever done before. Rainbow Dash would never “grow up” as it were since Fluttershy’s influence would always keep her in check. Sooner or later some pony would discover what had befallen Rainbow Dash, but until then there was a limitless supply of diapers to use, bottle to suckle, clothes to wear and games to play. And right now for Rainbow Dash, that was all that mattered anymore.