Book with a man married to multiple women who know about each other.

I am not looking for a sexual book. But rather a book about a dynamic of “sister wives”. I have seen some about the chattel-like nature of such an arrangement, and this would be fine. But I would prefer it to be from the perspective of this seeming normal.

I can’t say exactly what I am looking for, but this is somewhere in the ballpark.

Thanks for any suggestions.