My boyfriend has been joking about cheating on me, and breaking up with me. I am his first gf, and his first everything so I understand that he doesn’t know how to be in a relationship but I have talked to him about this, he’s recently started bringing up my past, I have been with many people before him, and I have had sex and he shames me for it. I tell him that it bothers me and he apologizes and says he was just joking. He stops bringing it up for about a week then starts again. What should I do?