Ya think?
Monkey see, monkey do.
Birds do it,
Bees do it,
Even monkeys in the trees do it...
Yeah, and how many things are there that you can do, really? Five? Eight, if you are really kinky? How did they judge what was being imitated, versus what just happens when people of opposite sex get naked together? So "their partners" observed various pairings of organs, and then did the same act? They wouldn't have the slightest inclination to do the same acts without the demonstration?