The grownups were shocked. The along came the jitterbug. Underwear could be glimpsed under flying dresses. Or maybe you're only old enough to remember the Twist.
Hips swirling in a hula hoop action, sans hoop.
There's a pattern here. Each generation does its best to find a signature dance that will not only define its spirit but also send the oldsters into fits. The only requirement is that each new dance craze must somehow go further than the last one. Therein lies the problem. Finally, dancing has gone too far.