Now, of course, this is coming from a woman in the lifestyle, but I have to say it: If it was me you were dancing with, and you were blushing because you were unsuccessfully trying to hide a massive hard-on that
I was to blame for...well...I'd have to say that would make me instantly hot. I can understand how it would be very awkward in vanilla situations, though, and I understand how it might come off as offensive to non-swinging women, especially if one or both halves of the dancing couple are already attached/married.
Chip,
you kill me! 2nten might be able to get away with the duct tape trick if he happens to be hairless, but I doubt he'd like it much when it was time to remove it otherwise. I know you mentioned that you wear boxers for work, but if you know you're going out or something, and you KNOW it's going to cause a problem, consider wearing some snug briefs. Apparently, if that's not going to cut it, there are such things as jogging briefs. Probably industrial strength nut-crushers, but - hey! - I guess it depends on how big a problem this is for you.
Other ideas:
BenGay?
Anti-depressants that kill your libido?
Slamming it in a door?
Thinking of Barney Gumble in a bikini...
Sorry I couldn't help any more than this...