Str8 men don't suck cock, gay men don't eat pussy.
I ate pussy. Actually enjoyed it, too. Does that make me bi? Technically, it does, I suppose, but is that how I think of myself and is that what I tell people who inquire about my sexual orientation?
Hell, no!
I'm gay. It'd be retarded to try and pass myself off as anything else. The number of cocks I've sucked (although, I usually manage to swing it so that it's my cock getting sucked) compared to the number of carpets I've licked is roughly 9/1.
I don't make any effort to pursue women for sex. The kind of woman worth having sex with requires too much commitment/foundation-building *cough*work*cough* to get to the point where they're comfortable going there. Ask a guy, "Wanna Fuck?" and they're naked in 2.5 seconds. For me, it's a no-brainer.
If a hot, cool chica that was purely interested in me for sex with no strings fell into my lap, I'd eat pussy again. But, the chances of that are like winning the lottery 100 times in a row. This is why labels for sexuality are basically useless. If I had to pick one for myself, other than "gay", I'd go with "homoflexible." To me, it's just easier to think of people in terms like, "He likes girls but will suck the odd cock, now and then." See? That's spot-on without all the trouble of having to wedge him into those basically meaningless categories like "straight," "bi" and "gay."
I'm sure I've harped on this before, but there's also a huge double-standard here because we're talking about men. Nobody blows a gasket when the sexuality of those college co-eds on the "Girls Gone Wild" videos comes into question. You never hear, "NUH-UH!!!! Those girls made out with EACH OTHER! Dude, that's SO GAY!!!!!"
When it's women, it's a non-issue. With men, it's all or nothing. Nothing less than acculturated homophobia hard at work.