When you're hooking up with someone but were friends before and after. Not as with friends with benefits where you are friends because of the benefits.
We've been benefits with friends for a while but are going back to normal status.
When a guy wears a strap on and fucks a girl with the strap on in her ass and his dick in her snatch.
Girl: what did you get at the grocery?
Guy: some milk to go with our double stuf whoreos.