Polyamory has a lot in common with Communism. In particular, they both sound really good in theory, and they both tend to dissolve into screaming fits or worse when attempted with real, live human beings. SF novelist Robert Heinlein did his best to make the open-ended group marriage look functional, and he did a good job of it. In practice, though… The polyamorous situations I have had occasion to observe have been emotionally equivalent to a roomful of people wearing nothing but blindfolds and hobnailed boots; sooner or later something soft gets stepped on, and then the screaming begins.
For myself, well, my wife and I are both Robert Heinlein fans, and that alone was enough to keep us from including an “exclusivity” clause in our marriage vows. Not that we really thought it would ever be an issue, but it just seemed to us that it was unhealthy to nail that particular door shut. Many years later, I am glad we made that decision; there is something in me that very much needs that door to be available, even if I never use it. It is one thing to say that the chances of my ever being involved with a woman other than my wife are vanishingly small; it is another thing altogether to actually VOW that such a thing will never occur. For reasons I don’t entirely understand, my subconscious identifies that vow with immanent death, and I am glad that it is not an issue.
Which brings us back to the larger issue. Once one starts thinking outside of the Post-Constantinian Judeo-Christian Monogamous box (and isn’t that just a HIDEOUS mouthful?), it certainly isn’t difficult to come up with situations in which a degree of intimacy between “spouse” and “friend” is appropriate. Simply allowing nature to take its amorphous and messy course is an invitation to misunderstanding and possible disaster.
It happens that one rather good answer is readily available within the pagan tradition, that of short-term handfasting. A relationship that begins with a vow before the goddess and a stated duration is unlikely to be taken either too lightly or too seriously, and even the most minimal ritual preparation guarantees that the information exchange that SHOULD occur, does occur.
“Beloved friend, I swear to you before the Lord and the Lady that I will always love you, that I will always hear you, and that I will never turn my back on you. I also swear to you, as the sun sets, that you will be the center of my world until the sun rises again.”