muscle and cock growth. Ripping clothes, too, pls...

Cadance offered Shining a wink as her horn shimmered. “Happy birthday!”

Shining could only blink in response. “Thanks, dear. I - whoa!”

A wave of nausea swept through him, but was quickly replaced by a spreading feeling of warmth. “Ugh,” Shining grunted, putting a hand to his forehead. “What - “

He stared at his forearm. Being the captain of the guard, he’d always been well-built, but his arm looked ready to burst out of its sleeve entirely. Rippling cords of thick muscle ran down from his shoulder. He flexed his hand experimentally, wondering at the new size. “Happy birthday, huh?”

“Oh, we’re not done yet,” Cadance said. Shining grunted again, but this time in pleasure.

His chest began to feel heavier, his pecks swelling outward with each passing second. His shirt strained, buttons ready to pop - and then gave up, buttons pop-pop-popping to reveal basketball-sized pectorals standing out proudly beneath his chin.

His shirt sleeves ripped right down the seam, Shining’s biceps swelling to twice their size, and then soon enough to the size of his head. His jeans fell to the floor as his legs thickened to the point where even Big Mac would be jealous - and suddenly there he was, his clothes on the floor, clothed only in the tatters of his shirt and a bulging pair of underwear.

And bulging they were. Shining’s eyes nearly popped out of his skull as he saw - no, felt, his hand twitching down over the growing bulge - his underwear straining to hold back a monstrous mountain of a cock. He moaned as his thick legs were forced farther apart by his growing balls, their sloshing cum warm and heavy.

With a snap, his useless underwear fell to the floor - and so did the last of his dignity. Shining glanced down - and down, and down - at Cadance. She was grinning, drooling, and winking…somehow, all at the same time.

He had a feeling that this was going to be a very long, and very enjoyable birthday.

“Fuck me,” Cadance whispered, and tackled him to the bed.