Go out with him and hint around a little like talking about a friend you know that experiments with other guys or other things along those lines. That way you are not outing yourself in case he isn’t interested yet are still leaving an opening for the conversation to go further if he is.
I once was friends with a guy for like two years and the only thing he ever talked about was chicks so as bad as I wanted him, I didn’t say anything as I was afraid I would alienate him if he knew. One day we were talking about porn and I mentioned that I would do gay stuff if I was making porn and he agreed. The conversation escalated from there and we ended up spending the night together which was hands-down the hottest sex I have ever had. I moved out-of-state the next week and fell out of contact with him but WOW was he worth the wait!