grabbing one's crotch is not strictly a sexual action. it has always been done by guys trying to look tough. "Deez nuts" and all that.
bending over and rubbing your ass on a married man who is singing a song about the supposed "gray area" between consenting sex and rape, (Blurred Lines, cuz Canadians are gonna fuck you whether you are passed out or not) and having her feign a rimjob on a big bootie black lady who is wearing a bear mask...
that is straight up sexual! MTV's target audience has been 12 year olds for about 20 years.