I, personally, have never had anything but gay sex: that is, sex between two gay men. But, a quick search on Craigslist or any similar site (or William's journal) and you see that the line can be easily blurred. Certain men will emphasize and cater to their "straight" counterparts, both parties getting off on the situation at hand and no pressure is put on classification or explanation. Straight men can have sex with men multiple times and claim to be straight as an arrow: that's obviously relative and arguable but then again, so is what makes a person attractive. Like beauty, sexual orientation and identity is in the eye of the beholder: or "beer-holder" if you're a T-shirt that some over-weight frat boy is wearing. Couldn't ring truer in this case.
Hey, did you all here that the McCain ladies LOVE gays families? That's gotta make dinner with dad a little awkward, when he firmly believes the opposite.