How do you handle it when someone does something annoying like check-raising you at every opportunity during a game?

Are there certain behaviors, like someone clicking or chewing gum with his/her mouth open, that bother you more than others when you play?

Have you ever "lost it" during a game? If so, under what circumstances?

Has anyone ever "lost it" over something you did either deliberately or inadvertently during a poker game? If so, what were the circumstances that led up to that moment? What did you do once the person calmed down?