Men and women dancing together has always been about sexual expression. Look at TV today, or movies, or music. To expect teens to dance today the way they did 50 years ago doesn’t make sense to me.
female bent over, grinding buttocks on the front of a male (or female) behind her... Maybe not the best thing for public school gymnasiums...
Maybe "dancing" is the wrong word. A far more accurate expression of this activity is "dry humping".
If your idea of (apparently inevitable) social “progress” means acting more and more like animals in rut, where do you suppose a stopping point is? Live sex in public? Threesomes in public? When, in your opinion, is enough enough?