Our room had a balcony overlooking the beach. On the night of the pool party, the wife was paying for going apeshit during the day, so I sat out on the balcony, listening to the music and watched security heavily patrol the beach. They made people come out of the water, but didn't seem to hassle the people laying on (and getting laid on) the beach beds.
Stacia has a habit of getting flash-naked at Patyos, which I tend to enjoy by the way, and Security has never said anything at all to her. Not once. We had a group of 30+ get naked and go whoopin' and hollerin' up in the Sports Pool at about 1:00 a.m. last August, and no security guys got upset at us. The water was cold though, so that shut us up quick enough, Ha! Shrinkage is a terrible disease. It must be cured.
The randomness may have something to do with how many creepers are in the crowd and not with what the couple(s) are doing. They are just following the order of the day from the top and sometimes in the Mexican tradition lining their pockets. I think tipping them to look away is a bad idea and would start a precedent, maybe tip them (with money) when your done and thank them for keeping you safe on your way out.