How to grind (freak dancing)?

So I understand grinding consists pretty much of the guy(me) moving in sync with the girl's hip movements.

My main question is- Assuming the girl is a complete stranger you just met on the dance floor, how long does one typically stay grinding with one particular girl? And after that period of time, how does one stop grinding with her(to go home, or to go grind with another girl, etc.)? I mean, do you just walk off without saying a word, as if nothing happened? And is it normal to talk to the girl afterwards, if she wants to exchange phone numbers, etc.?

I hope you can answer my questions accurately. If you don't want to generalize, please tell me what you would do in those situations! Please don't say, it's all up to you, etc. I'm on Yahoo Answers to get answers.. Thanks !!How to grind (freak dancing)?
usually it ends when the song is over, if yur really into the girl and the girls likes you and stays with you for over a song i think it would be ok if you ask her for her numberHow to grind (freak dancing)?
it basically looks like they are having sex with clothes on. its been banned from schools all over the place



why is this in the celebrity section why??
thrust.
it stops when she has a baby on the dance floor