Boyfriend being a jerk???

So I recently had sex with my boyfriend. All was good up until we were done having sex. He started being kind of rude to me. The next day I decided to have a chat with him about it and he said that he's getting more attached to me. He told me that he's being that way because we had sex now. I also brought up to him about how he was kind of distancing himself. He told me that it may feel that way to me but it means the exact opposite of how i feel. He is also being very protective now and gets really mad when I talk to other guys even though I talked to them before my boyfriend and I had sex. I'm just a little confused why he's acting this way?