Among the “great” civilizations only polygyny has ever been practiced.
The Comanche, for instance, moved from being a backwater tribe who couldn't do anything well, circa 1650, into being the dominant tribe in what roughly covers 2/3rds of west Texas, western Oklahoma and Kansas, large swaths of northern Mexico plus 2/3rds of eastern New Mexico and Colorado for the next two centuries.
They were avid polygamists as were most Native American tribes who lost a large part of their male population through constant warfare. It was a matter of necessity more than sexual gratification.
The Comanche were not very nice, to say the least, but most of the American southwest belongs to us and not Mexico because they kept the Spanish at bay for more than 150 years.
All of the generations of Jewish patriarchs from Abraham through Solomon's sons were also polygamists and the Bible isn't really clear on when the practice ended.
Not that I'm advocating it, just pointing out the the "wise Latina" at least has the sense to question where this grand experiment with marriage is going to end.
Like I told Vigilanteman, in my comment #142.
Wrong! Same sex marriage was common place in the Roman Empire. In fact Nero had his lover castrated and married him.
Even among many Indian nations, same sex marriage was common with males. It was not allowed for women, but the men did practice it. Women had no say so in anything they did.
Throughout history, societies have always had some sort of homosexual cultures that were accepted as normal. That is until Christianity was introduced and they realized it was a sin against the One true God.