Replying to Problem

I was at a party last night and this chick was grinding on me with yoga pants. Of course i get a boner which i thought was totally chill and what girls expect when they rub their ass against a guys dick. Well this girl freaked and told me I was immature and gross. I tell her what the fuck did you expect to happen? Did you expect me not to get a hard on with an attractive ass rubbing my dick? she says yea normal guys can control them solves. I respond you dont get it at all do you? then walked away and got my self to big cups of beer to knock down after that.  
I have never had an issue like this before and am wondering if anyone else has