I personally think in the real world there are LOTS of completely str8 guys who wouldn't think of looking even at another guys dick, ass, or whatever. The total thought of looking at another male in this respect is unacceptable to a complete str8. About the only thing a complete str8 can see, is maybe a friend that literally went from thin to bulked (how could you notice?) or lost a LOT of weight, etc.
I do think though, that while any str8 male will never admit it, can tell if another guy is good lookin tho. Even to the point of two males standing side by side and thinking that male is better looking than the one he is standing next to.
Gays, at least for me, depends on "which gay world" you are in. Some are total size queens, some are feminine, some really get into the whole gay stereotype. Others prefer to blend in and not make a big deal out of it. I'm gay and not ashamed to admit it either, but at the same time don't care much for a man that is effeminate or simply a size queen, etc. I consider myself a man regardless of my sexuality, I expect whoever I may date to be the same. They don't have to be totally masculine (another turnoff) but masculine mixed with just the right touch of conscience is my ideal mate.
Luckily I found him and have been with him a long time.
For the record, any gay types I can be friends with, some of the size queens and/or feminine types can crack me up totally. But as far as someone I am with, I guess I enjoy a man's man.