Now she knows!!!

Yep!!

"There, there, my dear! No need for such dramatics!" Lockhart said, stepping forward. "A simple sticking charm, to give you some modesty until we can sort this out! Adhaereo Vestis!" He tapped her shoulder.

It did reduce her breasts to their natural proportions. But the spell also backfired spectacularly. It didn't make clothes stick to her; it made her stick. Her skin became a powerful adhesive.

"Here, let me help you up, lass," a kind voice said. It was Seamus Finnigan, trying to be a gentleman. He reached down, placing his hand carefully on her arm to help her sit up. The moment his skin touched hers, it was as if he'd been super-glued. His hands were now fused to her arms, just below her shoulders.

"Blimey!" Seamus yelped, pushing on her torso with his other hand to give himself leverage to pull back, but it was useless. He was stuck fast, his other palm now pressed against her naked breast, causing Ginny to squeal loudly again.

Lockhart's eyes widened in what looked like panic, but was actually glee. "A fascinating side effect! The Epoxi-Skin Hex! Not to worry, a simple counter-jinx! Manumono!"

A jet of orange light hit Seamus. Instead of releasing him, it caused his hands to sink slightly into Ginny's flesh, squeezing as if it were soft clay. Her nipple bulged out from between his fingers.

Ginny let out another high pitched cry of embarassment, as her bare breast was squeezed with incredible strength in front of the entire student body, not to mention her professor.