The Slytherin

You circle the girls once, realising that the Slytherin is by far the easiest target of the group, grinning to yourself.

You wait for the best moment to strike, watching them take a couple of steps along the queue before snapping your fingers.

The shirt she had been wearing, which was already straining against her bosom, suddenly gives. The buttons pop off, shooting further down the queue, and the shirt swings open, flashing you, and several others the girls black lace bra, see thru enough that you can clearly see her nipples straining against the fabric.

"Fuck!" Slytherin yells, quickly grabbing at the sides of her shirt, trying to pull it closed across her bosom, but not before several more eyes turn to look at her, far more cleavage on display that had been moments before.