She notices

You decide that it's more fun to let her know her predicament and clear her mind for a moment. It's not long before a slight breeze picks up and she notices the cold wind on her bare arse cheeks.

Suddenly breaking from her yoga pose the Teacher brings one hand down, feeling the seat of her yoga pants and finding not fabric, but bare skin. Her cheeks flush and her eyes go wide but she's able to stop herself from actually screaming.

"Oh no!" she gasps, feeling at the fabric, a little shocked at how big the hole feels.

Her odd movements have of course now caught the attention of her students who all stare at her in confusion.