So class, what have we learned today about polyamory, the first root of the word meaning "many" and the second root of the word meaning, strictly, "love"?
If you answer that monogamy is a negotiated subset of polyamory, agreed upon in advance, you would be correct. Monogamous couples are a group that belongs within polyamory, not outside of it.
Furthermore have we finally set aside some of our assumptions about boys and girls? I'm not saying that you can change your sexual attraction, you can't. Ask any long-suffering asexual person.*
But you can put yourself in someone else's shoes... be compassionate... taking just a moment before you bite out of what you may feel to be a "moral right" yet completely breaks down in the light of actually examining the experiences and testimonies of people living under different systems of rules.
So let me just take a moment to blow your mind: The people who think long and hard about interactive dating sims** i.e. multiple choice romances often have to examine their own preconceptions and expectations of things while writing out some complex tales, sometimes going into over 100,000 words in fine form of "what a tangled web we weave!"
Real life can be quite similar.
With that in mind, do we not all have multiple groups of friends, usually multiple people you relate to on different levels? If you agree to be with one person for the rest of your life, that's a decision you arrived at between the two of you, no other entity on this earth is beholden to bow down to such a rule over something as complex as attraction and carnality and the higher-minded manifestations like self-sacrifice, endurance and shared victories and defeats.
_________ *Don't ask them, they've heard that question enough times. "Don't you want kids? Don't you want to settle down? Don't you want to follow this life path I assume every single person on Earth must want as a goal in life?"