Joke flag

A phrase used to describe discontent, discomfort with ideas or situations; Disagreement with peers, family members or a sarcastic statement referring to someone or their statement directly.

Group of friends are going to party. Someone finds out that "one of the girls in the cars" ex boyfriend is there at the party. They all ask her if its cool if we head out with her ex there? She says "JOKE FLAG!" along with a hand gesture.

Meaning: Hell No!, Not Going, Did you really just ask me if we're going?