Her panties fall down

Sandry was alarmed by a faint "twang", but glancing down quickly she reassured herself that it was nothing; her uniform looked like it was intact, so she got started on reading her presentation.

Halfway down the first page, she felt something sliding down her legs. Was she sweating? It felt light, just brushing her skin and raising a few goosebumps. Sandry tried to concentrate, finish her presentation and then she could go back to her seat.

She was just turning to the second page when she heard giggling. Looking up, she saw the students in the front row stifling laughter, and looking doen between her legs.

Confused, Sandry followed where they were looking. To see a length of red plaid material between her knees and, as she watched, dropping onto her ankles. It was around her legs, and the red plaid reminded her of...

Her "lucky" knickers! The ones she had put on that morning!

"Sandry!" Miss Lane exclaimed, noticing, "Your underwear!"

"Oh no!" Sandry exclaimed, facing rising laughter from the class, "Oh no, no, no!"

Covering her crotch with her papers, even though her skirt still just about covered her, Sandry hurried back to her chair. It was only when she got there that she realised she had stepped out of the panties, which still lay on the floor at the front of the room.