You're not wrong, but there's nothing wrong with wearing them even underneath a suit. You could give a surprise to someone you're fond of when they take off your pants.

But otherwise I'll wear them instead. You could even put them on me, if you'd be so kind. [ a hand slinks down her thigh, the svelte of her black dress; it's actually long and elegant, rather than short enough to bare her legs much. ]

It'd be hidden on me too, but therein is the appeal. Nice lingerie can be a secret to be revealed when time comes.