This is hysterical! I remember my mother telling me about this (without the Christian rock part). She said at dances, the nuns would walk around with a ruler and stick it between a couple if they got too close. There was also something about not being permitted to wear patent leather shoes.
I looked it up. There was a superstition (Catholics, of course!) that if the shoes were shiny enough, you could look up the girl's skirt. (6)
Not my kind of dancing-too far apart
Ain't nothin' wrong
With a little bump n grind, baby