Author's Note

We're in the penultimate chapter, folks. Just one more left. This is probably going to be where the ageplay themes are at their heaviest.

This chapter is loosely based on the mini story that Lucky Bass (MLPCutePic on Deviant Art) posted along with his (or her) solo diaper image of Pinkie Pie. As well as a concept Smity91 dreamt up for "A Mother's Touch" but never got around to implementing before his account was banned.

The Adult Foal Party

With her new sleeper safely in tow, Pinkie allowed herself to be accompanied back to Sugarcube Corner by Mrs. Cake. Rarity had made the sleeper to perfection, it was everything Pinkie had wanted and then some.

But the party pony soon started to think, and worry about how or if she should break the news to the rest of her friends. Rarity's speech had been pretty reassuring, but she couldn't speak for ponies like Applejack or Rainbow Dash who were sure to have a different reaction to it all. They probably wouldn't kick her out of the group for it, but it was a secret that Pinkie feared could strain their friendships to a state beyond repair.

The more she thought about it, the more Pinkie started to worry until it refused to leave her alone. "I've got to find some way to get this off my chest. Some way to know how my friends would feel." She thought to herself one day, as she was in her party planning cave with just a diaper on. By now she'd gotten used to having one on just about every other day or so, her "little" state of mind still thankfully stayed away whenever she didn't want it to come out. But keeping it under wraps around her friends was becoming an increasingly difficult task.

The pink party pony was thinking about a particular idea. It was one that even to her seemed odd, which was saying a lot considering she almost never found anything she did to be out of the ordinary. She was currently rummaging through the files she had on all her friends, all the while thinking about one thing in particular. "Can I use this stuff for my plan? How would I even go about it? I've never thrown a birthday party quite like this before," She paused in her pondering. "Come to think of it, I've never thrown any kind of party that involved diapers before. Does that make it a diaper birthday party? Would anypony even come to it if I called it that on the invitations? But if I don't mention it, then wouldn't I be lying? Wouldn't that make it ten times worse?"

Pinkie groaned as she retrieved the files and set them aside on a small table in the party cave. "Oh, this is driving me so loco in the coco!" She complained aloud. "Never before have I wanted to throw a party so badly, but I can't think of how to do it! Come on, Pinkie, think! There's got to be a way to make it work!"

Alas, despite several long minutes of silent thinking nothing would come to the planner's mind. There were a whole bunch of ideas floating around in her head, but it seemed like whenever she tried to reach out and grab one it would be just out of reach. Now she knew what Rarity probably felt like during her many occasions of "artist's block" as the fashionista liked to call it.

Thinking about Rarity caused Pinkie to reflect back to that conversation they had shared in Rarity's workshop almost two weeks ago. The young fashionista had mentioned having her suspicions but had not confronted Pinkie and Mrs. Cake then and there over them. She'd most definitely not been completely onboard with it, but had come to accept that it was a part of her friend. Mr. and Mrs. Cake had said much the same before, reassuring her that if her friends were to find out they would accept it even if they didn't necessarily agree with it.

So if she was going to go through with it, Pinkie decided that she might as well do it in a way that wouldn't be out of the ordinary for her. Feeling inspired, she started making the invitations. "Oh, this is going to be the best diaper birthday party ever! I can feel it!" She thought to herself.

The day before her birthday, Pinkie bounced all around town with a basket full of invitations for all her friends. The only thing that they said on them was: "You're invited to a special birthday party. Come to the back door of Sugarcube Corner tomorrow evening for a birthday party you'll never forget."

Every one of Pinkie's friends accepted, suspecting nothing (aside from Rarity, who seemed to give a knowing wink to the party pony).

The day of the party arrived soon afterward. That very evening, after not having seen Pinkie all day, six ponies and a dragon made their way to the back door of Sugarcube Corner as specified on the invitations.

"What do you suppose Pinkie has planned this time?" Rainbow Dash wondered. "I hope it's not like the time we tried to throw her a surprise party, and she replaced us all with inanimate objects," When Starlight shot her a puzzled look she explained. "Long story, you had to be there."

Starlight shook her head. "Sounds like I'm better off not knowing, I heard Pinkie acted rather... strange. Chasing you all across Ponyville and interrogating Spike."

"Well she did say she was sorry afterwards," Spike replied with a smile. "I'm just glad I'm not missing out on the fun. I wouldn't miss a Pinkie Pie party for the world!"

Meanwhile, Fluttershy noticed something as they approached their destination. "Rarity, you've been wearing a rather goofy grin for some time now. It's almost like you know something we don't."

Rarity tried to get the grin to go away. "Darling, you must be imagining things. What could I possibly know that Pinkie Pie wouldn't share with the rest of us? And even if I did know something, I wouldn't necessarily share it with the rest of you. Secrets exist for a reason, you know."

Twilight simply changed the subject. "We're here now, so there's no point in asking. Whatever Pinkie has in store for us, we're about to find out. I just hope everything's okay, yesterday was the first time I'd seen her as her usual Pinkie self in a long time." The alicorn then rapped a hoof against the door.

The door swung open and Pinkie happily greeted all her friends with a big hug! "Ooh, I'm so so SO glad you could all make it! You're just in time!" She quickly pulled them all inside and shut the door before any of them had a chance to react.

"Um, sugarcube?" Applejack commented as her eyes scanned her surroundings. "Why's it so dark in here? I can't see my hoof in front of my own face."

Pinkie giggled. "Didn't wanna spoil the surprise, silly! Don't worry, I'll get the lights!" As she made her way over to the light switch she cautioned. "You're not gonna believe what you see. But it's as real as everything else is."

At that the lights flickered on, the darkness vanishing! Everyone briefly shielded their eyes as they adjusted to the sudden flooding of light. When they opened them, they indeed couldn't believe what they saw!

There stood their friend, Pinkie Pie, in nothing but a giant diaper with balloons printed on the seat to serve as wetness indicators and pink tabs on the side. Surrounding her was a huge package of Silly Filly adult brand diapers that had clearly been opened, alongside things like a stack of pacifiers, sized up foal toys, and even wet wipes, foal powder and rash cream.

"Surprise!" The pink earth pony shouted in delight, blowing on a party blower she'd produced from seemingly nowhere. "It's my first ever diaper birthday party!"

A tense and uncomfortable silence fell over the room after Pinkie's revelation. Aside from Rarity, everyone just stood there in silent shock, no one could speak.

The silence was finally broken as Rainbow Dash burst into a fit of hysterical laughter! "Okay, Pinkie. I gotta admit, that's a good one! You went through all this trouble to set up this sized up birthday party for a foal! I totally didn't see this coming!" Pinkie didn't speak a word, but Rainbow kept on laughing. "C-come on, now," The brash pegasus insisted as her laughter started to cease ever so slowly. "T-this is all a joke, right? Right?! A-any moment now, you're gonna laugh along with me and we'll all admit you pranked us good."

Pinkie only shook her head. Realization slowly set in. "No way!" Rainbow exclaimed as her wings folded outward in shock. "You're serious?"

With a gulp, the party pony plucked up courage and finally confessed. "Girls, there's something about me that you don't know. Something I wanted to tell you a long time ago, but I didn't know how to put in a way you'd understand." That was all she was able to get out before her lips started to tremble and her body started to shake and shudder.

Rarity deduced what was happening and quickly stepped in to help her friend. "What she's trying to tell you, darlings, is that she is what is known as an 'Adult Foal'."

"'Adult Foal'?" Twilight shot a pondered look at Pinkie. "I'm... vaguely familiar with that term for some reason. I think I read it about in a book once, though I can't remember where or when."

"First I've heard of it," Applejack nervously replied. "Don't take this the wrong way, sugarcube, but just what in the hay is an 'Adult Foal' and what does any of it have to do with all of this?"

With an encouraging nod from Rarity, Pinkie found the courage to say what needed to be said. "An 'Adult Foal' is a pony who likes to act like and be treated like a foal. Diapers are a big part of it, but it goes beyond just that. I like to do all kinds of things that foals do. That's kind of why all these things are here, I don't exactly have a nursery, and I can't exactly share one with the twins."

"And you invited us here tonight just to tell us that?" Starlight questioned.

The party pony shook her head. "No, there's something more. I really wanted you all to accept this part of me, accept that I like to be this way from time to time. So I decided to make my birthday party an adult foal party," She tried her best to put on a smile. "It'll be tons of fun, I even got the Cakes to agree to be the caretakers. Don't worry, Cheerilee's watching the twins tonight, so it'll be just us. But I'll understand if you don't wanna join in. This is probably a lot to take in right now."

Twilight was the first one to trot up to Pinkie after the confession, putting a hoof around her friend. "Pinkie, it was very brave of you to tell us all this."

"Does this mean you accept it?" Pinkie asked.

Twilight nodded. "More or less. We know that it's a part of you, and it seems to be harmless. But it's definitely going to be hard to understand. We'll..." She paused. "...Probably need some time to think about joining in, even if it's just for this evening. But whether we join in or not, we're not going to magically stop being friends over something like this."

"Well, speaking as one of these friends," Rarity declared. "I for one intend to try out this 'Adult Foal' thing. After all, I was aware of it since before the invitation," She looked across to Pinkie Pie. "I assume we need to wear diapers for the party. But are we required to..." She coughed into a hoof. "You know?"

Pinkie shook her head. "Oh no siree. You don't have to use 'em. You just gotta make sure you ask the Cakes to use the potty. Foals can't do it by themselves you know."

The young fashionista sighed. "A bit of an unusual stipulation, but for the sake of our friendship and for the sake of the party I shall more or less 'play the part' as it were."

The pink party pony gave Rarity a hug. "Thanks, Rarity. I didn't expect you to be the first volunteer."

"Well, let's just say that my foalhood wasn't exactly the most 'ideal'," Rarity explained to Pinkie. "I don't think my parents were quite sure how to handle a foal. I remember them being more strict than seemed necessary, I could never get away with anything. Perhaps that is why they seem to have taken a more hooves off approach to raising Sweetie Belle. If not for my insistence, I'm not even sure she would've ever graduated from diapers."

"Great! Feel free to grab a diaper from the package! Mr. and Mrs. Cake will be up shortly to help you put it on!" Pinkie encouraged. "Oh, and one more thing, you gotta call them 'Daddy' and 'Mommy' while you're here. If you're gonna dress up like a foal, you've gotta be treated like one. Otherwise, it's not an adult foal party!"

Rarity retrieved a diaper from the package, trotting over to Pinkie while holding it in her magic. The fashionista curiously put a hoof to the undergarment, feeling its soft touch as it compressed in her hoof with a light crinkle. "Hm, it seems thicker than anything I remember Sweetie Belle wearing." She commented.

"Hey, thick diapers are the best! They give you extra poof for your padding, it even says so on the label!" Pinkie declared as she bounced over. "Trust me, once it's on you're absolutely going to love it! Think of it as having a comfy pillow, but on your butt! And, bonus, they come with really fun prints. Mine's got balloons on it, but the ones I got are special. They're designed to match a pony's coat and cutie mark. So that means you'll have gems on yours, Rarity. Your diaper might even sparkle like them."

Fluttershy fluttered over a moment later. "They sound really relaxing. I guess I can try them out for you, Pinkie. It'll be nice to be the foal instead of the mommy for once. Seems like I'm always taking care of little ones, sometimes I even have to diaper some of my baby animals just so my cottage doesn't get too smelly." She quickly helped herself to one of the diapers, holding it in her left wing.

"Well that's another good thing about the diapers," Pinkie grinned. "They've got absorbent filters to block out the smells."

"Well, that's... lovely, Pinkie," Twilight nervously commented as the young alicorn headed for the door. "But I think I'll pass on your offer, thank you." However, she let out a yelp when Spike unexpectedly got in her way and started pushing her back.

The little dragon groaned while doing so. "Come on, Twilight, you need to take a break. Even Princess Celestia takes one. And we both know what happens when you start getting stressed," He chuckled to himself as he added. "Besides, this time I get to be the older sibling."

Twilight pouted and grumbled. "Hey, I wasn't that bad at raising you... Even if I had my parents and Princess Celestia to help me." She struggled not to blush.

"Pinkie, we'll take two of those diapers. One for Twilight and one for me," Spike declared as he pushed Twilight forward. "I can be a big brother, right?"

The pink party pony nodded. "Yup. You can be as big or as little as you want. And did I mention there'll be tons of party games?!"

The mention of games brought over Applejack and Rainbow Dash, and Starlight reluctantly joined in taping up diapers around their rumps, so as not to feel left out. Mr. and Mrs. Cake arrived a short time later, and they could only smile at seeing the eight big foals in thick padding that were there to greet them (even though Spike was more a hatchling, and considering he was a baby dragon the diaper seemed to fit him perfectly).

It wasn't long after the diaperings were complete that the party games started. Pinkie Pie grinned as she and her friends faced a series of seven chairs. "This is just like musical chairs, but with one new rule. When you're out, you have to sit down on your diaper and you can't move at all until the game's done." She declared.

"Seriously?" Rainbow Dash groaned, looking down at the thick padding between her legs. She was still nervous about wearing a diaper.

Applejack just grinned, poking the thick padding between her legs. "Better make sure you don't lose then, sugarcube."

Rainbow smirked. "I won't! I hope you are, Applejack! You're going down! In fact, I have a hunch you'll be the first one eliminated."

Pinkie simply laughed and clapped her hooves. "Okay, everypony, places," Then she turned to Mr. and Mrs. Cake. "Start the music, please."

"Okay, Pinkie." Mr. Cake replied with a smile, turning on a record player.

The music played for about a minute, then Mrs. Cake switched it off. Everyone scrambled for a seat as fast in their thick, padded rumps, making adorable crinkles and poofs of foal powder from their legs. They scampered as fast they could! "You're out, Pinkie!" Mrs. Cake declared just seconds later.

Right on cue, the pink party pony pleasantly plopped precariously down onto her poofy padded posture. "Shoot! Oh well, winning isn't everything."

"You lost on purpose, didn't you, Pinkie?" Starlight questioned.

"I have no idea what you're talking about. Why would I lose on purpose?" Pinkie innocently replied to Starlight. "Just focus on yourself. I'll be fine on my own. Besides, in this case losing's more fun than winning."

Starlight shrugged her hooves. "Alright, I guess," She turned to the Cakes. "Uh, I guess we start the next round?" The music cranked to life a second later.

Round after round passed in the blink of an eye until finally it was down to just Applejack and Rainbow Dash for the final seat. When the music stopped, both scurried for the seat as quickly as they could! But in the end, with a poofy butt bump from Applejack, Rainbow was thrown off her chair and slammed down onto her padded rump, creating a cloud of foal powder that billowed from her leg holes. Thus eliminating her and causing Applejack to be declared the winner. "Yeehaw!" She cheered in delight and flashed a devious grin at Rainbow. "Better luck next time eh, RD?"

The tomboyish speedster grumbled. "I totally would've won if you hadn't bumped me out of the way with your diapered behind."

Applejack went on teasing with a grin. "You sayin' this diaper makes my butt look big? Maybe I oughta sit on ya, then you can tell me if you still think it does."

Fluttershy quickly fluttered in to break up the fighting. "Girls, there's no need for that kind of behavior. Pinkie never said butt bumps weren't allowed."

Pinkie nodded while laughing and kicking about. "Yeah, they're totally legal! And it was so hilarious when Applejack hit Rainbow Dash with one! Also, Rainbow, I'd suggest less foal powder."

"So, what's next, Pinkie?" Spike inquired, scrunching his diaper between his legs as he asked. "Are there more games?"

The party pony replied with an affirmative nod. "Yup! This one's a spin on 'Pin the Tail on the Pony'. Get it, spin?! Cause you spin around?!"

"What's the big deal, it's just 'Pin the Tail on the Pony'." Rainbow commented.

But Mr. and Mrs. Cake brought out a display that was nothing like what Rainbow or anyone else (except Pinkie Pie) was expecting. It was a pony with a multi colored diaper on it. "This game's called 'Pin the Diaper on the Pony'," Mrs. Cake explained. "It's just like 'Pin the Tail on the Pony', but instead of a tail you're trying to put a diaper on this pony."

"And as always, the guest of honor goes first," Mr. Cake instructed as he brought over a blindfold. "Are you ready, Pinkie?"

Pinkie happily bounced over. "You bet I am!" She was soon blindfolded and spun around as her friends all chanted. "Round and round and round you go! Where you stop, nopony knows!" After a bit of spinning she made her way around to the pinned pony. But she 'accidentally' missed its bottom and pinned the diaper to its head. "Whoopsie! Now that pony's got a diaper stuck on its head!" She snickered. "Boy, doesn't it look silly?!"

"I'll go next," Fluttershy encouraged, jumping up and down in her thick padding. "The diaper looks like it has more room to fit than the tail." And she turned out to be right, she was able to pin the padding on almost perfectly. And with the exception of Spike (who had an adorable waddle when he tried to tag the tail on the diaper), no one else came anywhere close.

The games went on for quite a while, but eventually it was time for cake. Everypony had bibs and Pinkie lead them all to a small refreshment table full of giant sized baby bottles. "Take your pick, there's bottles for everyone! We've got bottles of milk both regular and chocolate, apple juice, and even punch!"

"Is there any cider?" Rainbow asked as she licked her lips.

Pinkie laughed as she shook her head. "Silly Dashie, everypony knows cider isn't for foals. Just like coffee, that's a grown up only beverage." Then she took a baby bottle full of regular milk, bouncing over to her seat at a nearby smaller table, suckling from the bottle's rubber nipple all the while.

Everyone else quickly helped themselves to the bottles containing their preferred choice of drink (apple juice for Rainbow Dash and Applejack, chocolate milk for Starlight, punch for Rarity, and regular milk for Twilight and Fluttershy. Spike had crushed gems in his bottle of milk).

Mr. and Mrs. Cake waited until everyone was seated, before they brought over a cake with several candles in it. On cue, everyone began to sing:

Happy birthday to you!

Happy birthday to you!

Happy birthday, dear Pinkie Pie!

Happy birthday to you!

The party pony smiled. "Wow! Thank you all so much! I don't even need to make a wish, because it's already come true! I've got supportive friends, and a loving family! Two loving families in fact! What more could anypony ask for?"

"How about a change for one thing?" Mrs. Cake suggested, poking at Pinkie's diaper. "Haven't you noticed how soaked you are, my little Pinkie?"

Pinkie looked down at her diaper, noticing a damp patch spreading on the white padding. She could've sworn that hadn't been there when she sat down at the table just a moment ago. She blushed. "Oopsie, I guess not. Good thing I've got a mommy and daddy to notice those things," Then she turned to Mrs. Cake. "Can I blow out the candles really quickly? Please, Mommy?"

Mrs. Cake nodded in encouragement. "I don't see why not, Pinkie. Go ahead."

The big foal took a deep breath and blew out all her candles in the blink of an eye, everyone clapped and cheered. Then she rose from the table, slowly waddling over to Mrs. Cake, blushing as the diaper squished between her legs a little.

"I suppose now would be a good time for everyone else to take a potty break, if they want to." Mr. Cake offered, and a few hooves (and a claw) shot up.

Mrs. Cake worked quickly to change Pinkie into a fresh diaper, by now the whole thing had become routine. "See, Pinkie, after all those worries you had, your friends didn't judge you at all."

"I guess you and Rarity were right all along, and so was Daddy," Pinkie smiled. "This has been the absolute bestest birthday party I've ever had!"