Here’s a quick piece to illustrate one possible take:
It sounds like you’re setting up a scene or a character sketch — “the lingerie salesman’s worst nightmare” could go a few ways, depending on the tone you want (comic, dramatic, or psychological). the lingerie salesman's worst nightmare
But her — the woman who walks in at 7:55 on a Friday night, ten minutes before closing — she’s different. Here’s a quick piece to illustrate one possible
Derek’s mouth opens. Closes. Opens again. the lingerie salesman's worst nightmare