Author's Note

Written as a request through my Patreon, the user has asked me not to share their name.

Contains: Luna; anthro; ass expansion, public exposure, wardrobe malfunctioning

Full Moon

"I'm so happy you agreed to come," Celestia chirped as she walked down the busy streets of Manehattan. Her hooves clicked against the ground, and bags full of clothes hang from both of her hands. She wore a simple white dress, leaving more than a bit of her cleavage exposed.

Luna huffed at her side. She wore a black T-shirt and a pair of tight dark blue jeans, outlining the curves of her ass. "It's no big deal, sister." She too held a paper store bag in one of her hands, though far less full than the other's.

"I know you'd much rather be sleeping," Celestia replied.

"I think you're the one who might need sleep, those pants you tried to get me to buy were way too large. Are you sure you didn't stay up partying too long last night?" asked Luna with a giggle.

Celestia giggled back, an odd edge to her voice.

A subtle sound, like fabric tearing, barely audible. Luna stopped.

"Is everything alright, sister?"

"I... think so?" The alicorn wiggled in place for a moment. "I felt something odd. Must have imagined it." She started walking again.

Celestia waited for her sister to reach and pass her, then followed behind. From her position, Luna couldn't see her horn as it lit up again. She was more subtle this time, going slower with the spell.

"Are ponies looking at me, sister?" asked Luna after a while.

Celestia's eyes remained glued to the other's slowly expanding ass, the same ass gathering the stares of all the ponies walking by them. "I believe they are, Luna. Don't give it any mind. They're probably still getting used to the whole no longer Princesses deal, and they saw you so rarely before anyway."

"Sister?" Luna's steps were becoming stilted, a bit awkward. "Did you do something to my pants without telling me?"

The white alicorn bit down on her lip for a moment to stop a moan at the sight of the taut fabric in front of her. Thanks Harmony she was carrying bags, or she would have been grinding her cunt with her hands and not just with her magic. "I did not. Perhaps they are just old," she half-lied, while the sound of tearing began to echo once more from Luna's behind. Deciding she couldn't hold on any longer, she knocked Luna's bag out of her hands with a spell.

The gasp the blue alicorn let out was close to a moan. Her backside was on fire, and it felt so tight in her jeans. It was starting to drive her nuts, and she was already wet from the stimulation. Absent-mindedly, she curved down to grab back her bag.

As Luna bent at the waist, Celestia unleashed her magic in full. There was a loud rip, almost loud enough to cover Luna's lustful cry of pleasure, as the fabric of her pants was torn asunder and the full, massive naked size of her inflated ass came out into the air.

Everyone turned towards the alicorn.

Luna remained curved forward, moaning as the burning in her fat buttocks shot sparks of searing hot pleasure into her brain.

Placing her own bags in the hold of her magic, Celestia stepped forward, and delivered a powerful slap to her sister's ass. The alicorn's flesh rippled with the strength of the blow, jiggling and reddening where she'd been struck, and arousal sprayed from between Luna's thighs as she came under the tide of added stimulation.

Celestia simply walked away, one hand jammed beneath her clothes and onto her crotch, leaving the other in the middle of the road, with her fat ass stuck out in the air, moaning and drooling and dripping from her sex.