Disrespect

My boyfriend tends to put me down a lot. Most of the time he doesn't realize that he's doing it, honestly. He thinks it's funny and thinks that I should find it funny too. I've talked to him about it before and he said he didn't realize I felt that way and that he would stop. But a few days later he's doing it again and saying "I didn't mean it in a bad way" I'm really tired of it but he just doesn't get that it's really hurting me. What should I do?