I'm in an open marriage and have had a "partner" for nearly 3 years. We're not in an "official" relationship like gf/bf but we're FWBs, absolute best friends, fully in love, romantically and sexually and everything. We constantly say we're soul mates etc. Literally everything but the title, so he's technically single.

We had an issue at Christmas that he started seeing a woman and never told her about me and she expected them to eventually be mono and he didn't really accept why I was so upset with it. It fucked with my mental health and self worth so bad and led to a mental break for me. After that, we agreed that anyone he dated would know about me because I'm not going to continue being with him as a secret. We also both agree that ONSs don't need to know our situations.

He's started speaking to a new woman, literally only a couple days but he's excited about her and wants to ask her on a date. He hasn't said anything about me yet. But he also isn't sure what he wants to get out of the date - just sex or something more. He's fantasising about the future with her and coupley stuff but obviously he doesn't know her really yet, it's only been a couple days.

I don't think he intends to tell her about me before asking her on a date, but idk if it's my right to be upset? I don't want to ask him in case it comes across accusatory and he's not sure what he even wants so it could be irrelevant and I'm not even his girlfriend and probably never will be. He talks about other people being his gf/bf in the future but never me so I know there's an expiration date but that's hopefully a way off I guess?

Idk. Just looking for some insight.

EDIT forgot to mention I have it in my dating profile, he doesn't because he's technically single. I tell people straight away about both him and my husband.

EDIT 2 also just because reading this back I think my bias heaaavily comes through. From his point of view, he is single, doesn't know if it'll go beyond sex with this woman, and only recently broke up his his previous nesting partner so it's the first time he's actually been single in like a decade. He's figuring it all out as he goes.