Originally Posted by WhatHappened
I think the difference is that monogamy is typically part of what a couple has very specifically agreed to.
I actually don't see that as the case often, except in circumstances where when people meet, they are dating multiple people, and as things get serious they address the question about if they should "become exclusive". I know it didn't come up when I got married the first time, we just defaulted to it automatically without discussion because that's "what everybody does" It probably only comes up for most people if they have a religious ceremony where somebody says something about "forsaking all others" and not because a couple thought to sit down and discuss the topic.
I also know the second time I got married, we "specifically agreed to" 3 months of no new partners at one point, which turned into some years of monogamy, where nobody addressed the subject. I had no reason to think we hadn't specifically agreed
that we were going to be poly again when we'd been married for awhile and both felt secure about the state of our relationship. My husband seemed to think that we had just defaulted to monogamy automatically without discussion. It was just as much of a surprise to me when he resisted the idea of non-monogamy as it was for him for me to bring up being non-monogamous again.
I really like the things Kella said, very interesting way to look at it.