In for a penny

Smiling at the shocked looks on the faces of her pupils, you decide to up the ante a little further before the teacher can notice.

A snap of your fingers and the waistband of her panties snaps as well, slipping only slightly. All the while she's in mountain pose with her legs closed they won't fall far, but the top of her pubic bush is now clearly visible over the top of her panties, and it seems several members of the class have already spotted it.