Fwb gay?

So my fwb told me he’s bi , but never had sex with a guy before and only would want to do it if I was there . When we sext he is always asking about my bd dick , and if it’s big . And he always likes to hear about what me and my ex/bd did . I’m starting to think he’s straight up gay . I want to ask but I do t want to be rude is that normal . I’m not judging if so . I mean he does get horny super fast when he’s around me but he talks about my bd more then me lol. Sex is great with him it really is so I don’t want to stop .