Let’s confine ourselves to just one horny royal today, this being France’s Louis XV, who was a very busy lad.
Madame de Pompadour
…who wasn’t just his mistress, but pretty much the equivalent of his chief of staff (yeah, that staff as well).
Marie-Anne de La Tournelle
…who joined each of her four sisters as mistress of Louis XV. Ran through the family, he did.
Marie-Louise O’Murphy 
One of the few of all the royal mistresses who gave us a peek at her whole body, thanks to having been a model for artist François Boucher.
Madame du Barry
Now this was an interesting one. Not only did Madame du Barry go through the French court and nobility like a cleaver through a lamb — she must have had considerable bedroom skills — but she was also the longtime mistress of the grandson of Louis V, Louis XVI.
A multi-generational floozy! Sadly, though, the French Revolution’s guillotine was the last thing she gave head to.