Quote Originally Posted by OngBonga View Post
I don't really see why we still have laws against polygamy. The law respects equality when it comes to lesbians and bummers, so why can't three consenting adults have a relationship that suits them? What right has the law got to say to those people that what they are doing is immoral? Equality my fucking arse.
Historically and in modern times, polygamy almost always becomes polygyny, partially because females tend to exhibit hypergamy while men tend to prefer the opposite. Another contributing factor is that women tend to prefer serial monogamy.

With these conditions, open polygamy leaves an underclass of men who can't get women because the women "on their level" have a better guy than them. This underclass, which can easily reach a majority or near majority, is thought to become violent and revolt. Therefore, we have the convention of monogamy to try to damper that effect, even though men with means are often non-monogamous.