COOL! Roommate FUCKS me in the ASS!

Was that a good idea?! My roommate really wanted to fuck me in the ASS because his girlfriend won't let him. But can I just do it like this?! In any case, his horny cock was of the opinion that it would work and he was able to convince me of it pretty quickly. Finally I had another big cock in my tight asshole! Will his girlfriend ever find out?! Or do you think that was too crass?