I have no issue with men and women each having multiple husbands and wives, as long as all partners are adults and willing participants.

This means that if a woman wants multiple husbands (OR wives) and the other partners are fine with that, then I'm okay with it.

Like the Willow family on Caprica. That is a fine situation by me. A household of several men and women, all married to each other, all working together to raise all the children. How is that bad?

Where polygamy runs into problems is when it is only the men who can have multiple spouses, and those spouses aren't always adults when they marry, and don't always have a say in the marriage. THAT I will object to.

Of course, I would object to a system where only the women could have multiple spouses as well.

Like I said, if it is equitable, then it is fine by me.