I'm not writing this to attack that primary partner. I'm writing this to call myself out on being hypocritical, and naive, and just generally a terrible partner.
As I'm feeling out a potential new partner (and touching base with an old one), I'm realizing that I really do hate the hierarchy. I need to be so much more cognizant of the way I treat all of my partners, and not allow one of them to dominate my resources and time. I need to never ever allow a partner to demand that I make a change to the schedule, or to my roster, or to the way that I interact with another partner. Those are decisions I need to make for myself. If a partner has a concern about something, they need to discuss it with me and let me make up my own mind. If the decision I come to isn't one that they like they need to respect it and evaluate their own level of involvement.
It's a fine line to walk sometimes, not wanting to upset a partner while also making sure that your own needs are met and you are invested in each relationship to the degree at which you want to be. Polyamory requires constant re-evaluation and negotiation with each of your partners, and everyone involved needs to be equally informed.
The old partner that I'm touching base with made a wonderful point to me the other day. There were red flags for him in the time before we split up - concerns about the intense partner that he wishes now he had brought to my attention and talked through with me. But at that time, he was afraid that even broaching the subject with me would create battle lines, a him vs. us situation, and he was too afraid to lose me to reach out. In the end he lost me anyway. The reality is, had he spoken with me about those things, he and I might have worked through the problem and not lost each other. I might have grown up a little bit faster and saved myself a lot of heartache, too (probably not, but that's a whole other story).
I have asked him to please, in the future, always reach out. Always tell me the things I need to hear but don't want to hear. Always make me truly evaluate and question if something is too much, too little, or just enough. It's natural to be worried that a partner will get angry, but trust that partner to work past the anger and listen to what you have to say.
For myself, I am going forward with the knowledge that whether the partner in question is my husband or a man with a wife of his own, the relationship that we build is just as important to my emotional health as any other. I may not see them every day, but I certainly talk to them every day, and the time that we do share is sometimes more dear to me since it can be so limited. If I invite you into my life, you have the right to know whatever is going on in it, and to have your opinions about it heard.