flag flapping
On windy and even breezy days when a slutty woman's pussy lips can be heard flapping in the wind, giving you the impression there is a flag nearby.
Dude, do you see a flag anywhere around here? I can hear one, but I sure as hell can't see it. Oh wait, nevermind, your mom is wearing a miniskirt with no panties again. That is one flag flapping bitch!