This is interesting. I've just written a piece about the importance of what we ask and say on a first date--or shortly after we've met someone. We ask superficial questions but generally not the kind of questions that can make or break a relationship later on.

To your question -- while sex is obviously important, I disagree with the expert who believes sexual preferences are something to discuss on a first date.

In my opinion (and from experience) a far more reliable determination of sexual compatibility is whether you feel any chemistry right at the start. It's usually there, or it isn't.