Public breast expansion for Rarity during a party/ball. Anthro is optional. It'll be hot either way. c:

Discord snapped his fingers. For a pregnant moment, silence hung in the air. Then—

A shriek split the air. “Ack! My chest!” Rarity stared down at her bust, eyes wide. “Discord, stop this!”

All eyes were instantly on her. Rarity, who had started out the night with a not unimpressive bust size, had somehow graduated from “well-endowed” to “overflowing”. She was hugging at her bust, with her fingers curled around her rapidly hardening nipples. Her dress began to rip; more and more supple white titflesh was beginning to peek out around the sides of the fabric.

“Oh, but Rarity.” Discord all but trilled her name. In a flash of light, he vanished from his own corner. He reappeared beside Rarity, with one arm leaning on her shoulder. He inspected his claws, then grinned down at her. “I thought you always wanted to be the belle of the ball.”

Rarity watched with horror as her breasts swelled even further. Her dress was becoming almost unbearably tight. She moaned as the straining fabric mashed her two growing mammaries together, her now thimble-sized nipples rubbing against the silk. Two large damp spots began to spread across the dress.

“S-stop,” she gasped. She was now a size H, easily, if not bigger. And her breasts kept right on growing. Her knees wobbled as their growth rate redoubled. The weight was becoming too much for her. “P-please.”

Discord leered at her. His paw wandered down her bust—which by now had stretched out her dress something awful—and gave her rock-hard nipple a little squeeze. Rarity’s eyes rolled back, and her knees nearly gave out right there as a wave of pleasure rocketed up her spine. She could feel her nethers growing wet while a heat grew in her core. Biting her lip, she reached up to her neckline and gripped it tight.

By now, her breasts had grown large enough to each be the size of a small watermelon. Her cleavage was now incredibly conspicuous, and more than one stallion in the now-silent Gala had to turn away to hide his tented dress pants. Rarity moaned again as her legs spasmed, her breasts surging again in size. A long rip emerged in the seams, right down the center of her cleavage.

Discord grinned. “But you seem to be enjoying yourself,” he said, in mock surprise. “I would certainly never step in the way of a lady who knows what she wants. Although,” he added, his eyes glinting, “I may well help her along.” Before Rarity could even say a word, he snapped his fingers again.

Rarity collapsed to her knees at the same instant that her dress exploded off of her. Buttons went flying in every direction from her back. Some hit an unlucky guest; others landed in the cake or the punch bowl. One even shattered a window. Her bra landed on the chandelier. Rarity didn’t care. All she cared about were the two watermelon-sized tits weighing heavily against her chest.

She tried to reach around them, but the best she could do was cup each coin-sized nipple in either palm. She moaned as they throbbed under her touch, a low, throaty sound that mixed well with the lowered murmurs around her. Her tits squished and rippled between her arms, and she moaned again, slowly lowering one hand to her crotch as the other fondled her leaking nipples—

And then she seemed to remember where she was. Her eyes shot open wide. With an extremely ladylike shriek, Rarity made a futile attempt to cover up her massive mammaries with her hands. When that clearly didn’t work, she glanced around frantically for an escape route, found one, and made a break for it, her oversized breasts slapping against her chest every step of the way.

Meanwhile, Discord was laughing, applauding, guffawing. “Good show, good show!” he said. He glanced around the Gala and caught one gold-maned stallion’s eye. In a flash, he’d reappeared by that stallion’s side, with a claw around his waist and a paw on his visibly straining crotch.

Discord gave Prince Blueblood a wink, and vanished with a snap.