When dudes try to dance with you at the club...

What are we supposed to do, in your opinion? I am just curious because I've heard a large variety of responses from different females. In general, most girls seem to just dance when you "jump" behind, and most of them usually look back to see who they are dancin with and they will continue depending on how you look (I would assume) or if they know you. However, I have heard some females complain about that technique, and they get mad when dudes do that. Some of em will say that they'd prefer the dude to ask her first. It's nothin serious at all...just somethin I have been wonderin about.