The advice by Anymouse is absolutely correct. In any circumstance when it would be appropriate for a guy to ask a woman to dance, it's also appropriate for a woman to ask a guy to dance. My wife and I generally dance together, but we are both flattered when asked to dance by others, and neither of us would think of saying no absent some emergency. The only time I wince is when I'm asked to dance by someone who can dance at a level far above mine and that's an issue about being embarrassed on the dance floor and not appearance.

I have had instructors who ask you to switch partners during the course of a lesson, so asking a man to dance with you kind of falls into this same category. It's just a good experience all around to dance with others. My wife has even encouraged me to ask other ladies to dance at social events, especially if they have driven a long way to get to the dance, and don't have a regular partner there. I have had other women ask me to dance, though I can tell they are not quite as comfortable with that whole procedure. Men, of course, have it down to a relative science. But I would encourage women to ask. If someone says no, you ask someone else.