Two friends who have a tasteful dance is one thing. My dates have danced with male friends of theirs or mine in a couple of situations. I can even remember dancing with the wife of the man who owns the company I worked for then. But it was very respectful, tasteful and just dancing.

All this bumping and grinding -- mock sex really -- is another matter.

Tell her you don't like it and not to do it again. If she does it again, dump her.