What I wonder is, “How on earth would he know?”
For a start, the age of consent varies widely around the world (and even somewhat within the USA), from 14 to 18. Who on earth checks this stuff? Even within the USA, there is a patchwork of different ages. Is he supposed to have some aide who whispers in his ear, as he flies or drives from state to state, “Hrrrhm, Sir. It’s, errmm, 16 years old in this state”?
And even supposing the Prince happened to know what the legal age of consent is in any particular state (Florida, in this case, which has one of the oldest ages of consent), how is a chap, recently divorced, in the middle of sex party organised by a friend (not a very helpful friend in this case, as it has turned out) supposed to check whether the girls wearing make-up and high heels, but not much else, are 15, 17, 19 or 21? They would all look pretty much the same.
In evolutionary terms, women are physically ready to become mothers long before many of these ages of consent. Personally, I am in the camp that thinks that is a good thing if women do not become mothers until they are really quite a bit older than that. But if a woman decides to become a prostitute, or even to turn up to occasional sex parties for a bit of pocket money, before her local age of consent, it seems unrealistical and unreasonable to stigmatise or criminalise the objects of her attention.
There is an element of guesswork in the above. I have never been to a sex party. And it is far too late for me to start now.