Is my BF nervous about having sex with me?

We're both 21 years old. I'm gay and he is bi. We have been dating for a little over a month now and we haven't gone all the way yet.We have made out and done oral and stuff, I ate him out blah blah whatever, but we never had sex sex. We tried once but he was too tight and I wanted to be considerate so I told him that it was okay and we stopped.Keep in mind I am the top and he is the bottom. I am average so I don't see why he would be that nervous.I was cheated on by my last bf that basically told me that he lost all sexual attraction to me so I am scared it's going to happen again.Help? Thanks!