I personally wouldn't, and I'll explain my reason why.

I tend to me more skittish and nervous around guys, because in real life they scare me. I don't know why, they just do. But if I get to know a person and like them, then find out later that they're male, then I usually don't mind. If I can just look at people's genders, I'd likely about males like the plague where ever I could. XD And that would be a shame.