Lots of things are happening. I will say a few things:
dingedheart, you mentioned at some point that your wife was using a lot of "I" sentences, and saw it as entitled. You should know that using "I" sentences is actually recommended. It means explaining where you personally stand, and waiting for the other person to do the same. Surely, it would have been much more entitled of her to decide how you felt, what you were going to do and what you wanted. Saying how she felt, what she was going to do and what she wanted, though, is absolutely normal. It's her right as a human being. When she talked to you about it, it's possible she did so to hear what you wanted, in order to then make a decision together as a result.
When I came out as poly to my husband, I was very clear about what I wanted and what I needed, and expected the same respect in return. Instead, he lied to me and I only learned two months after our eventual breakup that he was actually mono. I would have appreciated not having been lied to for over two years. While it's true we probably would have broken up over it, this would have been a good thing for both of us.
I think standing up for what you want and need is a good thing. It doesn't mean you can't adapt to other people, as well. But sometimes it's irreconcilable, and there is no reason to lie to yourself or each other about it, because you're just dragging it out, and hurting everyone in the process.
"Deviant" is a heavily-charged word, whether it's correct or not. Using the N-word just technically means people who are black, not white or anything else, but it's considered pejorative. Same thing with the F-word and gays. And of course, deviant" has been used for gay people too, and while it's also technically true for them, I doubt they appreciate it anymore than we do.
Either you knew what the word implied, or you didn't. If you did not know, when told so, the normal thing to do was to profusely apologise for using such a horrible word without realising so. Instead, you backed up that you are technically right, which leads me to believe you knew what you were saying from the start.
I'm sorry you were hurt, but taking on the community here isn't a very constructive thing to do.
As for the initial conversation, it's hard, no doubt. I've had hard conversations, this one included, but many others as well. Your circus example is indeed an example. If you realise your partner has always wanted to join the circus, it's their dream, it's their life, I think you should support it. Maybe you'll go with them, maybe you'll wait for them, maybe you'll break up, but it's not your place to decide whether they get to do it or not, just like it's not their place to decide which option (following them, waiting for them, leaving them, anything I might have forgotten) you're going to pick. You can try to find a compromise together, so your kids can stay at the same school, for instance, but telling them, "Nope, you didn't say so before we got married, so that's not going to happen" is, in my opinion, contrary to the vows of marriage, which are about committing to the person and supporting them, no matter what happens (short of criminality, of course).
It doesn't mean taking any crap. You CAN leave them over it, if that's the best way to support them and honor yourself. But you don't get to dictate their actions, unless they pose a strong risk to their health or other people's. That's not how it works.