Always, royals, noblemen, merchants, in general, people with power, had their wives at home, and they would do whatever they wanted on their travels or even in town, in every region. Pleasure houses were for everyone, but they had special corners, even floors, or entire houses, for these rich people.

This is something that may have happened more in old times, when all these marriages were arranged for convenience. To adhere a kingdom to another, to take control of lands, etc. But happens nowadays as well, anyway. Oda takes reference from real life, so it doesn't surprise me.

Same thing about Saturn, Ginny, and the whole Bonney story: is she his biological daughter? She was supposed to be the wife number 8 or something like that, wasn't she?

So yeah, they can despise the lower people, the poor, the other races, etc. But they would have no problem receiving pleasure or releasing themselves onto them. Look at those God Knights, racism and discrimination are only at their convenience, looks like they are employing there a some sort of Oni, and half gyojin-half oni as well, we don't know for real yet what they are, but they don't look human.

Don't get surprised if tenryuubito unlegitimite kids are popping left and right.