'None of your fishnets' is an alternative way of saying 'none of your business' however it can be used in almost any location or situation, logical or irrelevant.
the unique mark left on the skin as a result of a high impact fall while wearing fishnet stockings. a common injury to a rollergirl, often as a result of a cement kiss.
Guy: What is that brutal mark on your ass from? It looks like it has hash marks in it!?
Ava: It's fishnet burn from where I fell playing roller derby while wearing a skirt, and it hurts like hell!