Reading some other folks' comments, I will say that my dating demographic at the time included a lot of folks with roommates, and I had roommates as well, so there were elements of safety in that if somebody had turned out to be a dick. First, talk to each other about the bases and decide that both of you are ready for this. All hands in one inning.
More than 50 aircraft, or about one in 30 of all produced, were damaged beyond repair. But from talking with friends of both genders, I think it is pretty clear that a lot of people don't see it that way at all. Response should ideally be enthusiastic and escalating, or at least passive but indicating clear contentment and pleasure. My suggestion if a guy starts pushing and tries again after you've pulled away, pushed his hands away, or however you've physically shown you don't want what he's trying to do..