Twilight looked through the books on her shelf, trying to figure out which books might hold the answer to the spheres use.

She had a nice lunch with her friends, but now it was time to get cracking!

She had just grabbed a book off the shelf when a surprise voice startled her.

This is so boring! Let’s throw a party instead!

“Bwah!” Twilight screamed dropping the book she had just grabbed.

“Pinkie Pie? I thought you left with the others!” Twilight said, looking down at the floor below her expecting to see Pinkie Pie standing there.

The library was currently empty however, Twilight being the only book horse there.

She shrugged and flew down to the ground, picking up the book and making her way over to the table in the center of the room to begin her research.

Just as she began to skim the first page, the voice spoke to her once more.

What’re we reading this old book for?

To figure out what the sphere does! Princess Celestia is counting on me!

This is soooo boring though! We should be making ponies smile!

Now’s not the time! We’re supposed to be-

Planning a party? Great idea!

Twilight found her body walking toward the door to the library, despite her not telling it to!

She tried to resist and turn her body back toward the table she was just in front of, but it was no use.

This had to have something to do with that sphere!

At least she still had hold of the book with her magic. Maybe she could find the answer on how to fix this!

But just as Twilight made this realization her magical hold on the book was lost as well, her magic levitating the book and depositing it in a basket next to a desk by the door marked “Returns”.

Twilight groaned inside her subconscious. It seemed for the time being, she had to go where her body wanted to.

Her body made its way through the castle halls and out the front door, making its way toward town.

This would have been a pretty usual spectacle for every creature in Ponyville, but Twilight’s body had decided to hop its way through town with a big smile on its face as she went.

Town ponies looked on puzzled as the Princess of Friendship made her way through the street like a school filly that had just gotten her cutie mark.

Why the heck am I bouncing? Ponies are staring at me!

Because bouncing is so much more fun than walking!

Twilight tried to get herself to stop, to try and ask somepony for help, but it was useless!

She couldn’t even use her magic to try and cast a spell.

Before she knew it, she had bounced all the way to Sugarcube Corner, transitioning back to a walk as she made her way through the front door and inside the shop.

The bakery was relatively empty at this time, as school hadn’t let out yet and most ponies had eaten lunch for the day.

Only two ponies at a table in the corner occupied the eating area, engrossed in a conversation about buck ball, and the Cakes could be heard in the kitchen, baking away.

This allowed Twilight to make her way to the staircase up to the living quarters without being seen, and then to the attic stairs which lead to Pinkie Pie’s room.

What are we doing here?

Silly Twilight, we’re planning our next party!

Twilight’s hoof reached out and touched the banister of the stairs that lead to the building’s roof.

The banister, shaped like a soft serve ice cream cone, activated, collapsing down and activating the secret trap door that lead to Pinkie’s Secret party cave.

“Weeeee!” Twilight screamed as she slide down the slide and into the secret room.

Twilight’s body made its way past the various party supplies to a desk against a wall sitting down in a bean bag chair and grabbing a file on the desk from a small stack.

It was one of Pinkie Pie’s party files. This one was about Silver Spoon. Her birthday was just a week away!

Twilight found herself going through and planning each pony’s party that was in the stack, from the food, invitations, supplies, venues, even a gift to give to each pony.

This would have taken any pony days to plan just one party, but Twilight found herself working through them at a rapid pace, filling out forms and invites with the necessary details before placing them in envelopes and placing them in a box at her side labeled “outgoing mail”.

Twilight actually found the organization and planning somewhat enjoyable. She almost forgot she didn’t have a choice in this matter to start with!

In just three short hours, all the ponies’ parties for the next month had been planned to a T.

That was actually kind of fun planning every pony’s parties. Now that that’s done, can we go back to the castle?

Twilight hoped since the voice had gotten what it had wanted that maybe it would let her have control of herself back now. What else could it want?

Good one silly! You know all the parties aren’t done yet!

Her body made its way back over to the desk, reaching underneath the table and pressing a button that resided there.

This caused a wall to click and open on the far side of the room, which her body began making its way toward.

I don’t get it. Why does Pinkie Pie have a secret room inside her party cave?

You know why silly! For all the secret parties some ponies don’t need to know about!

Twilight was shocked as she entered the next room.

It was set up much like the party cave, with a desk, filing cabinets, and shelves for party supplies, but these supplies were much different!

The shelves were adorned with a large variety of sex toys, suggestive lingerie, potions, lubricants, oils, movies, dolls, and all mater of items designed to cater to a pony’s special needs and fetishes.

Why does Pinkie have this room?

Because there’s lots of ways to make ponies smile! And one of the best ways is to make sure they have an extra fun time being honest with who they are with like minded ponies like them!

Twilight was trying to wrap her head around this logic as her body made its way over to the desk, taking a seat on the chair shaped liked a big teddy bear wearing a skimpy pair of underwear around its waist.

Her hoof reached over for a file and flipped it open. This one had Starlight’s name on it!

Upon opening the file, Twilight was greeted with a summary of Starlight’s most secret kinks.

Starlight Glimmer likes poofy pink diapers, incontinence potions, breast feeding, but she’s afraid of hiding games.

The rest of the pages showed pictures of Starlight with a diaper around her flank, some more used then others, playing with baby toys sucking on pacifiers, and even breast feeding!

There were other ponies in the photos too that she recognized.

Mr. and Mrs. Cake could be seen in a few photos diapering and feeding a few ponies in foalish garb.

DJ Pon3 and her girlfriend Octavia Melody could be seen humping each other’s diapers with looks of euphoria plastered on their faces.

Even some students she recognized from the school of friendship were in some of the photos, each enjoying acting like babies.

I…I never knew Starlight had this side of her.

Sure you do! You remember teaching her friendship lessons after she came to Ponyville.

You told her to make friends and told her to try and find ponies with things she had in common.

She confided in us about liking being treated like a baby filly, and we introduced her to ponies just like her so she could make other baby friends!

Twilight knew that wasn’t true. She figured Pinkie must’ve helped Starlight somehow find ponies that shared her odd interest, but how she found out about it was something she really didn’t care about finding out.

She had her own kinks, but definitely didn’t want them shared with ponies she knew!

Her body made a few notes like with the other party plans; how many diapers and potions to bring, what toys were required, and who to invite.

She finished all the required forms and put them in the outgoing mail as well.

Rather then proceed to the next file though; she began to walk toward the shelves of kink items.

Wha… What am I doing?

We have to try out and make sure all the supplies work for the party silly!

No! No please! I don’t want this! I’m not Pinkie Pie!

Twilight tried with all her might to do something. To run, to scream, to teleport herself far away, but it was no use. Her body wouldn’t let her.

Aw, don’t cry. Why should we act like a boring Princess when we can make everypony happy like Pinkie?

But I don’t think that’s—

Think? What’s to think about? I’m thinking we should just be like Pinkie. Besides, there’s lots more fun parties to plan here.

I don’t think I should be—

Twilight? You’re right; we tried that and all it ever got us was stress. Why not forget? Why not let yourself—

Be like Pinkie?

Yes! Just be like Pinkie. Just be like Pinkie. Be just like Pinkie. Be just like Pinkie. Be like Pinkie. Be like Pinkie. Be Pinkie. Be Pinkie. Be Pinkie. Be Pinkie.

The voice continued to coerce Twilight as it grabbed the supplies that needed to be tested.

A supper thick diaper, a nursing potion, an incontinence potion, a pacifier, and a vibrating wand were all gather and placed on the desk she sat at previously.

As her body unfolded the diaper and taped it around her plot, a loud pop sounded through her ears.

All her memories of learning math, science, history, and literature were swapped in favor of jokes, sweets recipes, and social skills.

Making every pony around her happy was what she lived for.

That and teaching everypony how to be a great friend of course.

Her average and perfectly healthy body began to transform as well.

Twilight had spent her life learning about and keeping her body in the best shape possible, making sure she aligned herself perfectly on her height and weight chart as she aged.

The new her had a much different idea about dieting and exercising.

Her stomach, which had been flat as a book cover, started to swell rapidly, inflating to give her a tummy that clearly enjoyed its fair share of sweets often.

Her petite plot and thighs also followed suit, growing to give her a beautiful amount of chunk that a stallion would not be able to keep his hooves off of given the chance.

Her breasts also received some extra attention. She had never had a problem with her B cup breasts, finding them perfectly fine for a pony of her figure.

Now though her boobs began to gain more and more mass like they were filled with dough, rising to a perky F cup.

Gazing at her left no doubt she was a pony that enjoyed her pastries as much as she loved getting to know new friends.

Her straight and tame mane and tail began to curl all over, shortening slightly; her mane loosing its bangs so her smiling face was always on full display.

Lastly her face, chest, and fore hooves each swelled up a bit also, leaving no doubt in anypony’s mind that she was a pony who didn’t give a buck what she ate as long as her tummy liked it.

As the changes slowed to a halt, the voice echoed the thought that became Twilight’s new reality;

Be Pinkie …

“Be… Pinkie …” She whispered softly to herself.

And when she opened her eyes that’s who she was; Twinkle Sky. Who she’d always been.

A big smile spread across her face and she felt the poofiness of the diaper strapped around her waist with her hoof.

“They pass the waddling and comfy test, now to test the other supplies!” Said Twinkle.

She took a medicine dropper and placed a drop of the nursing potion and a drop of the incontinence potion on her tongue. Just enough for the potions to take effect for a few minutes.

Moments later, Twinkle could feel her body feeling strange.

The space in her diaper became slightly smaller, as her F cup breasts became engorged with milk to a massive H cups that she could feel leaking into her diaper.

She could also feel her tummy rumbling, causing her face to contort.

She stuck the pacifier in her mouth and suckled profusely as she soaked the front of her diaper and loaded the back with a nice amount of pee and mess.

She laughed at the potions effects, giving them a passing grade as well.

Now it was time for the really fun part.

She grabbed the wand and switched it to max power, shoving it against her yellowed diaper front.

Even through the diaper’s thick bulk, the wands vibrations could be felt perfectly as they stimulated her breasts and crotch, making Twinkle cum in a matter of minutes into her diaper, panting in bliss as she switched the wand off and collapsed on the floor, mashing her mess against her.

After catching her breath, Twinkle spoke to herself, “These babies are gonna love this party so much they aren’t gonna wanna leave!”

She giggled to herself as she felt the potions affects subsiding, untaping the diaper from her wide rear and letting it fall to the floor with a plop.

She quickly levitated some wipes over to clean herself off in a jiffy before taping the diaper up and throwing it in the trash with the wipes.

She made her way back to the desk and made an order for some onesies, pacifiers, and wands to put in goody bags for everypony.

She then moved on to her next file. Filthy Rich.

She rolled her eyes. She didn’t really like catering to older ponies parties.

They tended to more enjoy just the sex without really getting to know everypony at the party.

But he and his business partners paid so well it helped her make other ponies parties special.

She made her way over to make sure she had her special lingerie in his favorite color set aside.

She pulled the bra over her head and made sure it rested tightly against her chest.

She then took the thong and pulled it up her legs to her waist, letting the elastic fly out of her hooves and fly against her flank with a loud snap, making her shutter in pleasure.

She looked at herself in the mirror, making a few sexy poses before giving her butt a smack, smiling as she saw it jiggle a little before settling back in place.

The other mares could keep their scrawny behinds. She knew she had what the stallions really wanted.

She giggled as she took the lingerie off and placed it back in its place on the shelf.

She skipped back to her desk and picked up the last file on her desk. Thunderlane.

This one was more of a special request. He wanted a wide variety of species to have fun with at his birthday party with a few like minded stallion friends of his.

This was not a problem for Twinkle however. She wrote letters to a few dragons, changelings, gryphons, and even kirins to come and show the stallions a good time.

But there was no way she was missing out on a party just cause she was a pony.

She strolled over to her potions shelf and picked up a vial and brought it back to her desk, taking the medicine dropper and placing a drop of the white creamy liquid on her tongue like she did with the other potions.

Her body began to tingle as changes rocked the purple alicorn’s body.

Horns sprouted out of her head, becoming long and pointed like a bulls.

Her tail lost hair, becoming long with a tuft of hair at the end like a cow’s.

Her mane grew out of control, gaining bangs that came down and covered her eyes while her mane lengthened into braids on either side.

Her torso became engulfed in fur, quickly consuming her legs, waist, and chest. She also gained a large hump that took up much of her upper back.

Her hooves became black and cloven, splitting down the middle.

Lastly her face pressed forward slightly and became a bit bigger, along with the rest of her body which grew to three times its size.

There was no mistaking what Twinkle was. She was a female yak!

The former pony looked at herself in the mirror and chuckled, her voice now a bit gruff sounding.

“I sure hope Thunderlane can handle this piece of ass!” She laughed whole heartedly.

As she looked in the mirror though, she felt she was missing something.

She stomped over to her collection of lingerie and looked through it until she found something that made her smile.

She picked up the panties and bra in her teeth and sat them on the floor before rushing over and grabbing a potion from the shelf, returning to the outfit and dumping the liquid on the garment.

Before her eyes, the garment began to get bigger and bigger, far surpassing any pony’s size before stopping.

Twinkle picked the garment up and slide the bra and panties over her yak body.

The hot pink outfit made her look all that more appealing as she gave her massive yak rear a shake.

It was at that moment the potion wore off however and Twinkle returned to her pony form with a poof of smoke, the panties and bra falling off her small frame and onto the floor.

Twinkled cracked up at the awkwardness of the situation before picking the massive garment up and setting it aside, making a note in Thunderlane’s file to bring it to the party.

All the parties planned, she turned around and exited her secret secret party cave, closing the wall softly behind her.

A lot of these kinks were necessarily her cup of tea, but they sure were fun to try!

She grabbed a piece of cake from her party cave and scarfed it down, making her way back up the slide and back to Pinkie Perfect’s room.

She had been so happy when her librarian had allowed her to keep her secret party cave hidden inside her room.

That made it all the more secret. Plus it made it a lot easier to order and make cakes at Sugar Cube corner for all the parties she threw to help ponies make friends!

Speaking of which, it was time to foal sit for the Cakes! She knew she was their favorite babysitter and couldn’t wait to see them!

She quickly made her way down the stairs to the two tots and their parents, with all the happiness in the world contained in her smile.

Author's Note

With the Mane 6 all believing in lives they never lived, will anypony be able to help them? Find out in the next chapter!