I think my boyfriend could be gay or bi but he won't talk to me about it. HELP!!?

Ok so first of all my boyfriend is a crossdresser. That should be known up front. We have been together about 7 months. About 2 months into it I found out he was a crossdresser. In almost every other aspect he is super manly. He's a roofer, watches football obsessively, ect. According to him he has been doing this for upwards of ten years (he's 23). It used to be sexual for him but now not as much. He claims it's about feeling feminine and pretty. When I first found out, I wanted nothing to do with that part of his life. My first thought was that he was gay. But since knowing, I have accepted it and also sometimes enjoy going out with him. He says he is absolutely NOT gay. He says he has no attraction to men. Here are my reasons why I think he's gay. First, the crossdressing. Second, he looks at tranny ads on craigslist. He says its because they're funny but he only looks at the ones in his area and some don't even have pictures so how is it funny? Third, while he was dressed we went to a gay club. I got wasted and we were propositioned into a 4some with a male female couple. They were turned on by his crossdressing. While doing this I guess the guy ate out his A hole. He says he thought it was me at the time. He also said it felt good. Fourth, he's really into (his own) anal penetration and even though it grosses me out I try to fufill what he wants. He also wants me to use a strap on with him. He says he likes it because men have that spot which I understand but being rammed with a strap on seems gay to me. Fifth, I'm a very attractive female. I have a very nice face and body and most men find me very sexy. He says he does too. But we're 23 and 21 and have sex twice a week (we live together) and that's after me basically begging. I'll try and get him in the mood and he'll say things like his stomach hurts or he's tired. He's a man. Shouldn't he want me all the time? Sometimes he even goes limp during sex or while I'm giving him head. Now I know with all these different things 1 and 1 equal 2. But he's always been open about fantasys and crossdressing so why wouldn't he about his sexuality? He completely denies it and says he'll never be gay. Honestly if he was I would leave him. I think I'm very open minded considering how much I already accepted but I can't deal with my man not being completely into me. I have never told him I would leave him over this nor have I hinted it. How can I get him to open up. This is killing my self esteem. I feel like if he's not gay then something is wrong with me. But, all the clues are there. I just NEED to know.