i can't believe you've done this - What you say when someone really, really bugs you and you're

What you say when someone really, really bugs you and you're just about to lose your mind.

"I can't believe you've done this" after someone kept making bad jokes for 10 minutes straight.

"I can't believe you've done this" when someone annoyed them so much they almost cried.

"I can't believe you've done this" after someone did something so stupid it was like watching a cat fight a robot.