Yeaaaah, as people said before it's that dance where teens basically try to have love with clothes on (if you think about it, a lot of dances are essentially that).
When I was in 7th grade in Hawaii we had this "field trip" where a bunch of samoan kids were gathered up from schools across the island and we went to this auditorium to dance. Pretty much 99% of the dancing was grinding, and there were guards there watching for inappropriate actions (the gym was filled with literally thousands of kids, I don't know what they were trying to accomplish). Either way, a bunch of guys got in trouble and had cuffs on and stuff because they were trying to have love. What people said in this topic is definitely true: Doesn't matter what you look like, if there's a dance with grinding you won't be left out.