What movie cliché do you hate with a burning passion?

For me, it would have to be the cliché where the liar gets exposed. They are either lying about themselves or something & when they get exposed or tell the truth, the other characters can no longer trust them or the liar leaves.

A Bug's Life, Easy A & Mulan are all guilty of this. (Although the cliché in Mulan is used quite well and it's a major plot point).

EDIT: Correct spelling