You'd think with rules on the books against discriminating on the basis of sex that it would be a slam dunk case, for this and night club covers, but there must have not been a serious legal challenge to the practice yet.

It's probably counterproductive. Yeah, you can sue and maybe you can win. But are you sure you want the end result?

Human attraction, unfortunately, is not very fair, and definitely doesn't really follow anti-discrimination practices, from everything I've read so far.