Why don't we ever see "gay but curious" in a personals ad?

The last few days have been strange, even by my standards. Which might be saying something.

I'm on the hundred-year plan to finish an undergraduate degree. I have finally begun to take classes again, and this semester I have two senior-level math classes, which started last week.

The first night in the first class, a very attractive woman sat in the desk beside mine. I mean, super-model-hot-girl attractive. Let's call her SMHG. I just made a mental note of her presence; I like guys, right? A young Brad-Pitt-cute-guy (BPCG) sat behind. Noticing him there: that didn't really surprise me too much. The second night of class (it's two nights a week), BPCG sat beside me and SMHG sat behind him. Guess who caused me the greater discomfiture? I'm amazed to report it was SMHG. What's that all about? I have no specifically erotic feelings that I can identify toward her. But I've lived my entire adult life convinced that such feelings weren't even a possibility, so would I even know what those were?

And guess what I overheard before class started that night: SMHG already has a master's degree in economics and is back to get a master's in mathematics. So not only is she gorgeous (we're in St. Louis, it's pronouced gahr-jus), she's a brainiac too. Yikes! Maybe I'm in love.