means "punch" and chops
means "mouth", so "to bust someone's chops" literally means to hit them in the mouth, but most of the time it means to give (someone) a hard time.
Don't bust my chops; I'm sick and tired of you calling me names.
To bust someone's chops (nonliteral meaning) is to say or do something that interferes with someone's line of expertise or leadership in something. Chops = skills or simply a person's line of action, especially at the moment; and busting = to stop something or interfere with something.
You always gotta bust my chops with some stupid remark during the TPS report meetings!