It’s really a twisted plot here. It’s something like this ... Noah and his wife have the three sons, one of which has a woman, but the other two don’t. So, what they’re going to do is take the two young girls of the first brother, for themselves ... you see ...
At least that’s what I understand from having read about it. I won’t be going to see it.
I always wondered as a kid how Adam and Eve with two sons begat the entire human race.