I don’t know that it is something where people are capable of having a preference. The knowledge of how babies were created (mixing man’s sperm with female’s eggs) created a scenario of possession and ownership over the product. That subsequently created jealousy from which marriage and many social structures spring. If that knowledge had never been discovered, that children were the random gift of God, then sex would be with whomever, whenever and for whatever reason (as I imagine it was in ancient societies before the knowledge of gestation.
Now polygamy can still likely be practiced, but it will take conscious thought to overcome the jealousy inherent. I do believe that people are capable of loving more than just one person for love really is action, not a state of being. But there will be favorites, vying for favorite positions, infighting and other subtle distractions in a polygamy which will make the progress of the relationships a bit more difficult. There are other benefits, particularly if children are involved. Now I’m also presuming here this is a multi polygamous society with multiple males and multiple females.
If your hypothetical is about Multiple wives or Multiple Husbands for a solitary entity, I’m against it. That is a power structure, not a love structure and isn’t mutually beneficial for all involved.
Please, think wisely before getting married to avoid trouble.