An Irish Leave
When you are so drunk at a party that you just leave without saying goodbye to anyone there.
Dude Rob is belligerently hammered right now, it would not surprise me if he gave us an Irish leave at some point tonight.
reverse irish leave
An announcement of leaving only to linger longer.
John was annoyed that Jane stayed so long at his party after disrupting the guests with overly dramatic, attention-starved antics like hugging, high-fives and other reverse irish leave moves.