Don't push it against me. I don't like it. I will keep dancing if you pull back just enough to keep it mostly off me. As long as I can tell you're making an effort not to rub it on me, we are cool. If you start rubbing your erection on me like I'm expected to let you get yourself off on me, I'm out, and you're lucky if I don't hurt you on my way out.
About a year ago, I experimented with this, to make sure I wasn't missing out on something. I let some random guy grind his hard dick on me while we danced at a reggae club, and you know what? After a while it hurt. It still hurt the next day. So I went a few weeks later and danced with some more random guys. I wanted to be sure the one dude didn't just suck at it. Plus, our crotches had not been the same height. The most fun I had was with guys who let me feel them getting hard, and then immediately pulled away. There was one in particular who was really attractive to me, and kept cracking jokes and asking interesting questions while we danced, so I kissed him and accepted his number. Would have called him too, but I lost it. The ones who just seemed to be trying (poorly) to fuck me through our clothes invariably turned me off, but I let them for my experiment, and tried to get into it and grind back. It was never possible to line it up with my clit, so there wasn't that kind of stimulation. And they invariably pressed too hard, even if I pulled away slightly to reduce he pressure. It left me with spots that stayed tender for days.
The guys were all smiles and wanted to exchange numbers. I thanked them and declined. I even stopped going to that spot for a few months because I wasn't running into the one guy I wanted to see, but I was encountering the grinders. Since I could see no polite way to say, "Don't talk to me. I don't actually like you. You were just an experiment and I tolerated you," I decided to avoid them until we all forgot what we looked like. Or at least until I forgot them.
Yeah...keep your dick off me unless I ask for it. I don't claim to speak for other women, but I find it disturbing, rude, and it hurts.