Hi All! Looking for some advice because I'm not sure how I'm feeling is valid. I feel like all of a sudden I'm bad at poly.

TL;DR: current partner thinking about getting back with an ex and I feel threatened.

Background: I've been poly for 18 months during which time I've had a divorce and 2 other serious partners plus some great dates. I (45M) am currently dating Brittany (38F) and have been for 5 months. She has one other partner who I've met and we KTP well together (not a triad). We're very compatible personally and sexually and have grown very close, to the point we are considering cohabitation in summer '24.

I never really felt envy or jealousy of other partners in other relationships so far in my poly journey. I've read all the books, hundreds of hours of podcasts, etc. Clearly I have more to learn, but I've done a lot of work so far.

On Sunday, Brittany said she had been talking to her ex Jonathan (2 years together, 1 year apart) and wanted to do a scene with him. I told her I wasn't comfortable with that. And yesterday said she had some big conversations with him and she wanted to start up their relationship again, with a meet intending to sleep with him coming soon. I've been kind of in shock since then. I feel very threatened by her Jonathan, and no amount of reassurance is helping. My ex-wife reassured me of the strength of our relationship right up to the day she asked for divorce, so words feel empty right now. I feel like there's a huge amount of couple's privilege between her and her LTR former Dom.

I've been hurt pretty badly several times the last couple years, have a 30 year history of abandonment trauma, and I've just recently been able to start imagining a future for myself and someone else. Getting divorced really destroyed my vision of a happy future. But if I'm just lining up for another hard breakup and dumping, I feel like cutting bait now.

I have talked to her about if her needs are getting met (yes), and I don't think I'd feel the same way about her taking a NEW partner, but her reuniting with an ex with so much history feels like a Really Big Deal™️ to me.

Help me Poly Wan Kenobi; you're my only hope!