My partner and I have been poly since we got together, but they have only recently decided to search for other partners. They said repeatedly since the beginning of the relationship that polyamory is the right relationship structure for them even though they would absolutely always be polysaturated at one. I would always say they could date if they wanted, and they were adamant that they can't be attracted to more than one person at a time.

Fast forward to now and they have decided to start dating and they very first person they meet on a dating app they end up having a huge crush on. Of course I'm happy for my partner! But damn, am I so fucking jealous. I've dealt with jealousy in the past with partners and metas, but it feels like something is different this time. Is it because I feel mislead? Because this is my fiance and primary partner? Because we're long distance at the moment and this new person is not?

This is like, intrusive thoughts, dreaming about it type of thing. Woke up thinking about them being intimate. Distracted if I'm on my own date while this partner is on theirs. My partner made an offhand comment while we were doing something else that I was sure was a reference to the way they described doing something intimate with this new person, then I felt really silly when they said of course it wasn't.

And to add to it, my partner says they like it when I am possessive/jealous, and sometimes it is really hard to swap between being playfully possessive and seriously supportive. And then there's the wariness of this person being much older and having said a few sus things... So I'm trying to put all that aside so as not to seem like crazy jealous, you know?

Anyone have some good reading or tips on dealing with jealousy?