bust (one's) balls
1. vulgar (acting upon oneself) To exert a significant amount of energy to do, accomplish, or complete something, especially with great haste. I've been busting my balls all night long to get this presentation ready for tomorrow's meeting. She's going to have to bust her balls if she wants a place on the varsity team.
2. vulgar (acting upon someone else) To harass, nag, or upbraid someone to do, accomplish, or complete something. The boss is busting everyone's balls to get the project ready by next week. Quit busting my balls! I'll get it done eventually!
3. vulgar (acting upon someone else) To tease, ridicule, or mock someone, usually jocosely. Don't get so worked up, man, I'm just busting your balls. I like her family, but her uncle always busts my balls when we see him.