Hell, in those days even the women were slapping the men on their butts! I should know, I got mine slapped in clubs a few times. :D
Still, slapping butts is really a far cry from sexual harassment, if it's only done mutually. These past few months have been a storm of sexual harassment allegations of FAR worse than hand on ass.
Speaking to a prior post, it is more than just a shame that some greedy company would not pay the daughter of their cash cow fair value for his work. Greed corrupts incredibly well, and the larger the dollar value, the fewer morals get in the way of some.