when hell freezes over

Idiomatic expression used to describe an event or scenario that is so unlikely that it will likely never occur.

Q: Dude, I'm tired of the beach. Wanna go and ride that fake, plastic wave that they setup at Wal-Mart?
A: Yeah!
Q: Right on! Let's roll!
A: Hold on, I'd rather do that when hell freezes over. You stupid nincompoop.

63👍 40👎