don't let the door hit you on the way out
Definition from Wiktionary, the free dictionary
- (idiomatic, sarcastic) Used to indicate that one is glad, or at least unmoved, to see someone leaving.
- don't let the door hit you in the ass
- don't let the door hit you where the good Lord split you
- good riddance
good riddance — see good riddance
used to indicate that one is glad to see someone leaving