"Fun" is a mightily subjective issue here. As long as both parties find it funny, that's fine. But even though personally a) I'd probably be too lazy and not upset enough to take any legal action if a stranger touched my family jewels, and b) don't have a soft spot for stiff upper lip PC, I fail to see the fun in anyone getting harrassed and/or sexually touched without her/his consent.
And frankly spoken, subtly(?) "encouraging" people in service jobs to be good sports as opposed to medieval-to-1939 squares so that others can have their(!) "funny" way strikes me as pathetic.