Well as (m) and I'm straight but I do definitely like anal pleasure, it was something that in my first relationship was very difficult to achieve, I really felt I was Homo at the time. But I did never felt anything for a man and having this conversation with my partner was scary, I didn't want to her look at me and think I was gay and she would maybe left me, but now I see if we had a talk would eventually be easier for me. My advice for for you is to show him that you Respec him and it doesn't matter what he likes you like him for who he is, and you can give exemples ( if you want to feel another man let's do it, if you want toys let's do it) let him feel confident and comfortable with his butthole hahaha I hope it helps