How do I tell my boyfriend I want to do anal?

I've done it before and absolutely loved it but I 100% get the feeling from him that he's never done it before.  He's more experienced than me but not with a lot kinky stuff.  Anyway, I just don't know if he's interested and I don't want to bring it up because I'd feel really embarrassed if I said I wanted to and he thought it was gross or something. Any words of advice?