Grabbing in Spain

I was in Spain this past april for a school trip and it was one of our last nights there. Not really experiencing anything too horrible yet we went to some clubs on a friday night. going into the club there were a bunch of guys around our age, maybe a little older who were outside trying to get in also. they made a few comments outside, but my friends and I walked away. a few minutes later we saw them near us in the club, and they started trying to grab us to dance with them. None of us wanted to so we stayed away and used the power of our big group to watch out for each other. pretty soon they were back and one older guy was grabbing at my hips to dance with him. I said no I dont want to dance and quickly got away. Later as we were leaving the club I was walking out with my friends when all of a sudden I felt someone grab my ass! I was shocked and turned around as fast as I could to catch the one who did it. I saw the group of guys but I didn't know who had done it. Needless to say, we got out of there quick.