I'm gonna explain it really simple. It's about kink, precisely some kind of an incest kink. Two sisters sharing and swapping their husbands, that's hot. As much as I know Zarah have only one sister Rabiah, and Rabiah is married to Omar, so there is no other possibility for that kink in here. So as long as it's optional, I will take this option.
Or other scenario, same kink. Two young adult girls, swapping their dads/stepdads, not dad and uncle. Still takin if it's optional.
Cuckolding, stealing others wife from the other hands, no, I don't like it, even if it's MC the guy who steal. And I still want to have action with Rabiah, just without cheating, cuckolding.
So the only thing that We ask is to accept and don't shame that others have different kinks. Each have their own.