Can you show me where the bible says he couldnt have multiple wives under the law and what his number of wives has to do with your question about Bathsheba?
I could be way off here, but I believe that the point that is being made by Sonnet is within your point, but from a differing perspective.
It seems a bit morally skewed to differentiate multiple "spouses" / possible "marriage concubines", and then go forward and say that adultery is simply sex outside of marriage agreement or with someone else's "property" (so-to-speak).
The moral compass of polygamy is displeasing to Sonnet, from what I gather, and I believe he finds it contradictory that a simple property right of marriage could allow an individual to pour romantic and sexual energy into more than one committed relationship.
I could be wrong about his general tone in this discussion, but he has a valid point of observation.
In short speak, it appears that men and women are free to have a harem of "committed" lovers, or at least men are, if there is indeed a double standard.
People just can't "swap" a committed harem partner.
This is an odd point, and it seems a win for the Mormon's practice of multiple wives.... for now.
Isn't this odd?