Hello reddit,

I have managed to enter quite a convoluted relationship set-up.
Some background: I am tending towards monogam-ish relationships, I am mostly submissive and tend to focus on one main partner strongly.
However, in the past, I got together with a polyamorous person (among others, due to the high overlap between the BDSM and polyam-communities), and the relationship was polyamorous on their side, and open on mine.
After we broke up, I continued to be non-monogamous - while I do *like* to give up control, it feels weird to me to, by default, end existing relationships because a new person entered my life.
When not deeply in love, but "just" being physically and emotionally intimate with people I care a lot about, that works pretty well.

However, I really really love the idea of living with a partner, and sharing large parts of my life with them, and (potentially) having a family with them.

Recently (a few months ago), I got together with somebody new, and it strongly clicked for me. I feel very submissive towards them, want them to be my dominant, and my life partner, and would like the opportunity to be there to have a family together.

The twist is their newness to ethical non-monogamy. They desire this as a relationship model. However, they are in love with a partner who doesn't, and who would prefer to be monogamous with them. When we first got together, they told me that the other person is a friend with benefits. they later clarified that she loves them.

Recently, we talked about vacation, and I proposed something. She answered that agreeing without discussing that with her other partner would feel really bad for him, and that she wants to plan a vacation with him, first (they had had a fight because she mentioned to him that she wants to go on vacation with him several times, and he didn't really react to her wish. My proposal to go on vacation was unrelated to this, I had wanted to offer that anyway, but I am aware that from the outside, it could look like I am trying to make him look bad).

The thing is - if she is trying to manage his feelings around going on a vacation, I doubt that she will have a family with me. If "other partner gets to go on a vacation before me" is something unacceptable to her other partner, "other partner has a child with my partner" probably is so by a lot more.

I am uncertain how to navigate the situation, and how to create some clarity for all of us. I would approach this with patience, but my partner is 32, and I am 40, so I can't delay the family planning phase indefinitely.

Any advice on how to communicate lovingly, non-violently and constructively around this topic is welcome. Also advice on what you would do in my situation :-)