How serious would you take it if someone called you a c*nt?

A guy who was my friend (we've had a long past) called me a c*nt last night and told me to go f*ck myself because he was angry at me. He was angry at me because I told him he had been harassing me (he always questioned me as to why I made the decisions I made). He said today he apologizes and he said it out of anger. My mom always told me that word is one of the worst words to call someone, so I'm just wondering how you would handle it if someone said this to you. Or if you would just brush it off and forgive him.