Thanks for writing this. I didn't know about some of this. I've talked to potential partners about polyamory a few times, but each time I mention how much information I would need to engage in this kind of relationship, they tell me that's not how polyamory works - that all partners are allowed to do whatever they want and no information is supposed to be exchanged.
So apparently, that IS a thing. But yeah...not my thing. If I were to do that, I'd need information. Consent. Conversation. Definitely.
And I'm sorry he treated you that way. <3