Do whatever you want because I sure don't care. Frequently sarcastic although one may genuinely be so over the friendship that they really are apathetic about it.
Used especially when you want to be done with someone who is choosing to be a jerk instead of being decent. A good way to end a tense conversation when you want to show your anger & disapproval of the other person's behavior.
Cade told his coworker on Thursday that he was going to call in sick on yet another Friday before a 3 day weekend, leaving everyone else to pick up the slack again. His coworker replied, "Suit yourself," hoping that the boss would finally fire him.