How do I start grinding with a girl?

Okay a party is coming up and I REALLY wanna grind at it but here's the problem. Alot of people have been telling me to NEVER ask to dance/grind or whatever and just go up and do it. But the thing is, it's so god damn weird if some RANDOM *** guy just goes up from behind to a girl and starts grinding... it's like what the hell. Is this really how you're suppose to initiate grinding with a girl? Also what if the girl is in a group? I feel so nervous going up to the group of girls to grind cause all of them are probably gonna be thinking...wth does this guy think he's doing?How do I start grinding with a girl?
it depends... make sure you smell pleasant of course ;) and then walk up from behind or front (while she's already dancing) and start normal dancing and ask her if she'd like to dance. NO you dont just start grinding on people lol. If she wants to dance then ou slowly get closer the maybe you can grind.How do I start grinding with a girl?
when you see a girl you may be interested in, just go near her and start dancing (but dont be creepy about it).. then put your hand out and bring her in closer to you and dance face to face for a second, then spin her around and grind with her!