I maintain you're going to find more straight guys, who've had contact (beyond a friendly slap) with another guy's butt, than you will guys, who've deep-throated their best bud's ween or had likewise done to theirs. I'll go so far as to say that even guys, who haven't had any ass-play themselves, know more guys, who have, than guys who've sucked another dude's wang or been sucked off by another guy. Can't say why that's so or what it says about how we view one act or the other; it's just the way it is.
Ask any guy, any age.
As soon as you can get your tool properly hard, you're looking for something nice and warm to shove it in. For a while, you don't care where, so long as it gets in there! Maybe, it's just nature.
Every adult male knows this, so why are we BSing here?
I guess what's gayer or gayest to do is whatever that most guys will tell you for sure they've never done and don't know any other guys who've done that, either. That's about as scientific an answer as you're going to get here.