by Innuendos
Is it not a polygamy (with consent of all parties) better than a monogamy but with a mistress/lover (with or without consent ) on the side.
My characters would certainly agree with that statement, as their marriage (specific to their case) is meant to be a relationship between equals, rather than one taking the lead, while the other is relegated to lesser status.That's not a pleasant situation to be in when both persons have the same feelings for their shared spouse.
Of course, they do have the benefit of being fantasy characters who have achieved a balance - in reality that balance would no doubt be much harder to achieve and maintain without a concerted effort on the part of everyone involved.
They also don't have a lot of the baggage that tends to be associated with "real" polygamous relationships: religious overtones, incestuous elements, or semi-misogynistic controlling relationships.
As for polygamy over monogamy? I'll leave the judgment of that particular fantasy to peoples' personal tastes. I know that some find the polygamy to be a squick, with polyamory being less of a problem.