Luna's Failed Cake Heist

by Amepix

Rating: teen
Tags: Princess Luna, My Little Pony: Friendship is Magic, Fetish, Comedy, Princess Celestia
Length: 3035

In which Luna tries to steal cake from her sister's private stash

It was the perfect plan. She'd been planning it for months, learning every little thing about Tia's private cake stash, and just when her sister would go in and out of the secret room. As night fell, Luna insured her sister was asleep before heading out from her bedchambers and into the halls under the cover of her night.

Things, however, do not go as planned.

Contains: Rapid Magical Weight Gain, Force Feeding, and Fat Ponies

Story and cover art done by me
Proofread and edited by ShayTheDog

My first ever story being posted here. What a first to do, huh?

Published 2024-10-27 20:30:01 UTC
Last updated 2024-10-27 20:30:01 UTC

Mission Failed

Luna quietly trotted down the halls of Canterlot Castle, moving through the ornate hallway with determination. She was invisible to the naked eye, thanks to a spell she had cast. It was oh so creatively called “The Spell of Invisibility”. The great wizards were not so great with names.

Anypony who had a good knowledge of magic could cast a spell to detect life, which would instantly reveal Luna's whereabouts. But thankfully, it seemed only Bat Ponies were on guard duty tonight. She was glad since she really wanted to pass by undetected. Meaning there would be no magic users around, Luna could sneak by unseen.

Once the Princess of the Night was outside the doors to the dining hall, she teleported inside. She knew that opening the door would probably make noise, so teleporting inside was the best course of action. Nopony was in the dining hall, which was connected to the castle's kitchen—Perfect!

She uncloaked herself, since she didn't need to waste any energy now that she was alone. Trotting down the dining hall with a slight spring in her step, Luna smiled. She was finally going to claim her prize: one of the cakes from Celestia’s secret stash.

Luna had pleaded with sister to share, but Celestia had always refused, telling Luna to get her own stash of cakes. Luna had a better idea. She'd be doing her sister's fat flank a favor by taking one of those cakes off her hooves anyway. Maybe Celestia wouldn't get plumper than she already was.

As Luna crept into the kitchen, she moved herself towards Celestia's private pantry. She knew where it was as she had spied on her sister one time she used a hidden mechanism to access it. Pulling a ladle on a nearby rack to the right, the wall right next to it split, opening up the secret doorway.

Luna smiled again, waltzing into Celestia's secret pantry to sample a cake. Surely her sister wouldn't notice, it's not like one cake missing from a room of many would be that noticeable, right? Right!

As she stepped into the room that held those “sweet delights" hit her nose, taking in a whiff of the scrumptious cakes that now lay before her, the midnight blue alicorn's eyes grew wide as she saw the room before her.

Luna could hardly beleive her eyes! . There were shelves upon shelves of cakes that were all being magically preserved so that they were just as fresh and delicious as the day they were baked. There was even a large table in the room, completely covered with even more cakes. Luna had never seen so much cake in her life. And she was starting to think her sister might have a problem. But right now, she was here, and decided to savor her reward.

Rubbing her hooves together with a gleeful smile, the Alicorn looked at all the cakes, wanting to find one of her liking. Her eyes soon locked onto one that made her mouth water... the most exquisite, chocolatey, melty, hot and absolutely delicious looking molten fudge lava cake Luna had ever seen. It had to be hers! She NEEDED to try it!

She took the cake with her magic, levitating it over to the table and finding a clear spot where she could place it and sit down. She didn't question why there was a table with seats in the room, or why not all of the plates had had anything on them. Normally, it'd be a bit odd that one of the platters were empty when all the others had a cake on them. But, Luna didn't think about that. In front of her was the most delicious dessert she had ever seen, and that was all that mattered.

Taking a seat, Luna cut a slice of the cake with her magic once again, bringing the chocolate delicacy to her mouth and biting down, letting out a loud and blissful "Mmmph~" as she devoured the slice of chocolate cake. Truly, this would be the greatest midnight snack, and Celestia would be none the wiser... or so she thought.

"Enjoying yourself, sister?" Celestia asked, causing Luna's eyes to grow wide in shock and panic.

"Tia?!" Luna yelped, turning her head around to see Celestia standing just behind her with a devious smirk on her face.

Celestia gave a knowing smile, causing Luna’s eyes to narrow as she watched Luna's reaction to being caught off-guard. Celestia could see right through her little sister's antics, her own eyes narrowing as she spoke up.

"Did you think I wouldn't know what you were up to?" she asked in a playful, teasing tone with her head cocked to the side as she continued staring down at her sister.

"B-but how! You should be sleeping! No, I saw you sleeping!" Luna exclaimed , in utter disbelief at the fact she'd been caught.

Celestia gave a slight chuckle at her sister's attempt to save face, a tiny smirk on her lips as she watched her sister squirm."This is hardly the first time you've attempted to sneak into my private dessert stash, isn’t it sister. I knew you had a sweet tooth, but to go to great lengths to steal from me..." She gave a playful and teasing grin, glancing at the slice of cake Luna had been eating.

"Well, you wouldn't share! So, I am only doing what is right,” Luna protested. "Besides, one pony shouldn't have this much cake to themselves anyway. Especially not a pony of your size, sister." Luna said, gesturing to Celestia's not-so-thin frame.

Celestia’s hips had gotten very wide over the past few months, and Luna wouldn’t be surprised if they were brushing against doorways after a few more. Her belly had rounded out into a plump barrel, one that would wobble around as if it were a water balloon filled to maximum capacity. Her thighs certainly weren’t as trim as they used to be either, having plumped up more considerably around her hind legs. Not to mention her flanks, which had grown to the point they resembled two squishy orbs squishing against each other. Her fatter flanks had also stretched her sun cutie mark out, making it look larger.

"Oh, is that so?" Celestia chuckled, her smile continuing to grow across her face as she crossed her forelegs and stared intently at her younger sister. The alicorn then stepped closer to her sister with an eyebrow raised.

"So, you think that I should be eating less cake, huh? Is that the excuse you're using to steal from me, dear sister?" Celestia taunted with a devilish grin

"Your fat flank could use less calories," Luna snarked.

Celestia chuckled at her sister's boldness. Of course, she couldn't deny that she could cut back on sweets a bit, or maybe go for a jog every now and then considering that she was looking more like the princess of Fluffy White Clouds than the sun.

"Well, thank you for your thoughtful insight, little sister. But perhaps you should take a look in the mirror sometime. After all, if anyone could use less calories around here..." She chuckled, playfully poking her sister's stomach.

Luna looked down at her stomach, only to have her eyes grow wide in utter shock and confusion. It bulged outward, and jiggled a bit from Celestia's poking. Luna continued to stare in disbelief at her chubby body. She didn't look like this an hour ago!

"Wha-?"

Luna’s belly was sticking out a few good inches before her, resting on the seat of the chair she sat in, remembered as well, and they connected to her bulbous, malleable hips. Luna could practically feel her flank softly squishing against the seat.

Celestia's smirk widened with her sister's reaction, as the alicorn reacted to her changes with shock and utter confusion. Oh, how amusing! Why was normally such a slender, trim and toned mare now getting chubby? Not in such a bad way mind you, but she was nowhere near as svelte as she used to be.

"Seems that your own words came to bite you, dear sister," Celestia responded with a snicker.

"Tis impossible!" Luna yelled, turning to Celestia and huffing with anger. "What hast thou done?!"

Celestia's grin widened as she continued to chuckle - her sister's reaction was absolutely priceless! She wasn't sure how long she could keep her confident act together before she began to burst out laughing as she continued to egg on her sister's anger.

"Me? Not a thing, little sister. I didn't do anything at all! Other than this, of course" she replied as she poked Luna's stomach again.

Luna's belly jiggled in response, causing Luna to blush from embarrassment. "What magic have you cast, sister?! I was not like... this before!"

Celestia could hardly contain herself after seeing her sister's blushing response. She couldn't help but giggle aloud as she continued to poke and prod her sister's chubby stomach - all the while she couldn't help but tease further.

She then raised an eyebrow and smirked as she spoke up. "Oh, but if I were to tell you, it would spoil the fun of this now, wouldn't it?" She said coyly, continuing to giggle.

"So you did do something!" Luna growled, pointing a hoof at her sister.

Her sister's growl made Celestia's smile even more pronounced, as she giggled some more.

"Of course I did! But come on, where's the fun in just telling you what I did? Isn't the thrill of not knowing what happened just a bit more exciting? You must admit, sister, your new figure is... amusing."

Luna grew angrier at the fact her sister had called her fatter body... amusing! She opened her mouth to yell again, only to be met with another slice of the chocolate lava cake being shoved into her mouth. The cake was surrounded by her sister's golden magical aura.

"Mmmph?!"

Celestia laughed a bit as she continued to shove the cake slice into her sister's mouth. "Eat, my little piggy sister. Eat as much as you want, it'll only make you fatter." She chuckled, continuing to feed her sister more slices of the chocolate lava cake with her telekinesis.

Luna's eyes grow wide at her sister calling her that. She felt her face turn red with anger before she felt a tingling sensation in her body, as she watched herself expand further.

Celestia couldn't help but let out a giggle as Luna's face went from anger to horror as her body continued to expand! The sight of her sister struggling against being fed cake she had begged to eat and blowing up like a balloon as she did was too hilarious for her not to.

"Oink oink!" She jeered, continuing to use her magic to expand her sister's belly and her waist. Oh, what a delight...

Luna could feel her butt start to hang over the sides of her chair, each cheek swelling with fat to the point where they looked more like beach balls than body parts . She could feel the blubber in her thighs start to force her legs to press up and rub against each other, which only made her more embarrassed... let alone the fact her sister just oinked when she looked at her.

And Celestia was still stuffing cake into Luna's mouth! undoubtedly, this was the coughing of her rapid fattening.

"Mmmph!" She let out, only able to make muffled noises with her mouth being constantly stuffed with cake.

Luna's muffled noises as her cheeks bulged from being packed to the brim with cake was music to Celestia’s ears. Her sister's embarrassment and utter shock at her own expanding body was the best entertainment she’d seen in a long time.

The sight of her once slender and toned sister being inflated into a flabby blob of a mare was absolutely delightful, as she continued to telekinetically shove slices of cake into her sister’s mouth-enjoying watching her force fed into absolute obesity.
Perhaps this would teach her an important lesson about what would happen if she messed with her precious dessert stash, and tried to pull a fast one on her.

"U-ugh..." Luna groaned as the last of the chocolate cake was swallowed, her massive, bloated gut groaning in discomfort as she let out a loud burp.

It had been quite a lot of cake, after all, as her belly had expanded into a positively enormous size with the copious amounts of sugary confections she consumed - which was the most entertaining part of the scenario.

In the now creaking chair sat a Luna who resembled nothing of the figure she had when she entered the room. In front of her was a bulging, bubbling, groaning belly that jiggled at the slightest movement, resting heavily between her thighs that she was forced to spread out to make room for the girth that was her stomach.

Said thighs had also increased their girth, wobbling like gelatin as Luna tried to shift in her seat to make herself comfortable. A task impossible in a chair that was now far too small for the blubbery Princess. Her massive hips spread out far past the edges of the seat, hanging down heavily and dragging Luna’s flanks with them-nearly to the floor.

Her face flushes red at the sight, a burp soon escaping her chubby face. The action causing her cheeks to jiggle, and her new double and triple chin to do the same. The blue Alicorn groans again at the fullness in her stomach.

"Hm, you sound a bit full, pig sister. But you do have a bit more room in your belly, don't you?"

She then teleported yet another slice of cake in front of her sister's face and smiled.

“...N-no…” Luna protested, disgusted by just seeing a new cake in front of her.

Celestia chuckled as she watched her sister's immediate response, and her belly grumbled loudly, still in discomfort from how much Luna had been forced to eat.

"Aww~ did I overfill my little piggy sister's belly? Or are you willing to try and make room for me to stuff even more cakes into that blubber of yours?"

Another slice of Chocolate Lava cake was teleported and floated in front of Luna's face, hovering just above her face and tempting her.

"...I think I've had enough cake for a millennia, thank you..." burbled Luna, rubbing her gut to try and ease the pain of fullness.

"Oh, are you sure?" Celestia smirked. "If you think so, then I shall respect your wishes. But if you're truly full..." She then waved her right hoof around, and all the fat Luna had gained vanished in an instant, as she was trimmed down back to her slender and toned physique.

"Oh sweet and powerful Faust, it wasn't permanent!" Luna sighed a heavy breath of relief.

"Oh, and you thought it was permanent, dear sister?" Celestia chuckled as she grinned and smirked, her own sister had really taken the bait. "Of course not..."

"I would never allow such weight gain to be permanent on any soul. Just a bit of harmless fun, that's all.” Celestia reassured. “But…if you ever think of stealing from my dessert stash again," she continued "I won't be quite so gentle next time..."

"You don't need to worry about that. I think you just gave me a fear of cake," Luna responded

"A fear of cake?" Celestia smirked, The Alicorn gave a small chuckle, as she spoke once more.

"You're not actually afraid of cake, are you, dear sister?"

"Sister," Luna gave her a stern look.

The solar alicorn couldn't help but chuckle with a small, mischievous smirk forming upon her lips as she noticed her sister's serious facial expression.

"Yes, dear sister?" She said in a playful yet teasing tone.

"Your fun is already over, so I request you cease."

"Oh, and just how do you intend to stop me, dear little sister?" The white alicorn smirked back, her tone of voice sounding taunting, almost threatening.

"I could easily feed you another cake in this room, couldn't I? And what if I choose not to undo the spell?" Luna smirked.

Celestia's smirk quickly changed into a nervous expression as she considered the fact that her younger sister could very well retaliate in a similar way.

"W-well, I..." She gulped, as her mind started to ponder the negative possibility of what would happen to her if her sister decided to not undo the spell - if it was even possible for her to do. Luna was a skilled mage after all… just as skilled as Celestia!

"Now, let's just go back to normal. You rest so you can be productive for your daily duties, and I'll get back to my nightly duties. Deal?" Luna asked, raising her hoof for a hoofshake.

Celestia gave a sigh of relief as her sister extended her forelegfor a hoofshake. She was happy to go back to normal. Maybe she had gone a little too far with this prank. even if she was still a little sore from the fact that her sister stole from her dessert stash...

"Hmm, very well. I suppose your suggestion is a wise one. I'll happily return to my duties." She gave a small smile and extended her right hoof for the hoofshake, ready to seal the deal.

"Sleep well, sister. I'm sure you'll have plenty of duties requested of you tomorrow." Luna smiled, shaking hooves with her sister.

"I'll be sure to do as such." The alicorn smiled as she then let go of her younger sister's hoof, before she waved to her and started to walk backwards as she walked out of the room. "Goodnight, dear little sister."

"Goodnight, big sister." Luna said, taking her leave by teleporting into her own bedroom to begin her nightly duties. Under her breath, she muttered... "Chubbylestia."

As Celestia left her cake pantry, she muttered under her own breath… “Moonpig.”

Author's Note

Well, there it is. Read all the way down here huh? Well, thank you very much for reading my first of hopefully many stories on here. They'll be whatever I want, so expect variety