Also, in the early days of wrestling with a huge change, going from mono to poly, it is important to remember not to have discussions that last more than an hour. It's important to have these hard talks when you are well-rested, well-nourished, and hydrated. Just having quit smoking is making you both all the more short-tempered. It's important to quit a conversation when one or both of you get "emotionally flooded." You will end up behaving badly and saying the wrong things.The only time I feel I blundered is when I think of arguments or points I didn’t make. The way this is described, you made your points, but unfortunately, she couldn’t or wouldn’t absorb them in the spirit in which they were delivered. Without a transcript, I don’t really think you blundered, so you might want to let yourself off that hook.
In hindsight, you should have given her the reading material, then followed-up on its being read, talked about the relevant topic in the material, i.e., poly hell or whatever, and THEN set up a cuddle date or an action plan, to smooth things over.
It's unclear from your post if it was your expectation that she would read the article, and then make more of an effort to demonstrate some type of team spirit, or whether she expressed an understanding of your concerns, and the ideas backing up your concerns, i.e., the reading material, and THEN had agreed to a late night/early morning “connection time."
As you say, her side isn’t represented, other than how you remember it. However, I VERY VERY much think she crossed a line. She knew this discussion/argument was going out to a 3rd party (her bf Pete) who is involved in some ways. There were lots of ways she could have handled that! Either she could have stopped you, saying, "I’m on the phone," or she could have told Pete, "I’m sorry, I have to hang up now. I’ll call you back."
Also, I think you made the right move in leaving, even if it was an hour early. I’m assuming, from your previous posts about your codependency, that walking away like this was a good departure. It should send a signal that lots of changes are happening and that your words and actions have meaning.
You have an autistic child, and that makes everything more complicated and stressful. Your wife might be having Mommy burnout. She might be exhausted from being at the beck and call of her neurologically different child for X number of years. So, the lure of sexy fun chat with Pete will be all the more exciting and compelling and obsessive. She's willing to overlook your own burnout and stress at being available 24/7 to meet the needs of your son. She's on that NRE high, and everything else in her life has become a pale shadow.
You also experienced the unreality of anything beyond your own NRE for poly itself, when you went to the bar and mingled with drinking, singing strangers, and didn't stay masked or socially distanced the entire time.
Hormones are a bitch. Some experienced polyamorists HATE NRE, and these are the reasons why. It makes us almost literally lose our minds.
Let me just add here that it was extremely unfortunate that Pete overheard your conversation, which you thought was private! I blush in embarrassment for you. Yikes.