Her skirt gets trapped

As Emma rolls the book cart along the aisles, you give a little wave of your hand.

As you do, a previously unspotted nail appears on the book cart, snagging on her skirt.

All it takes is a little forceful push of the cart and suddenly Emma's skirt rips. The sudden yank pulls Emma from her feet, knocking her backwards, landing hard on her arse, her tight black thong now on full display to you and revealing that she was wearing stockings, not tights.

"Oh god!" Emma screams, climbing to her feet and giving you a good view of her arse as she darts over to the book cart, trying to retrieve her skirt.