My (former) LO is jealous?
So, for a bit of backstory: I have been in an open relationship with my partner for 8 years before I met my LO at the beginning of last year, who was friends with my partner, and I quickly became attached to. We got close to each other, and I slept with him. I started developing feelings. He seemed to like me too, but because he was friends with my partner, he stopped our sexual relationship. Didn't want to be a home wrecker, yada yada.
I spiralled, went non-contact, broke NC, had a meltdown, and went NC again. I realised I wanted a polyamorous relationship, communicated, and repaired my relationship with my partner. I started talking to and seeing a couple of people between August and October until I met my now boyfriend, who I am very happy and content with him and my long-term partner.
After being with my boyfriend for a while, my LO was invited back into mine and my partners home for my partners birthday party, and after that things were friendly between us again (though I never got close to him like I was previously). He often comes over to our place to hang out and usually stays the night.
Cut to now: I've been with my boyfriend for 7 months, things have been going well with it all, me and my partner and I are solid and happy. The other day, LO was at our house to chill with my partner, but I had plans for a games night at a friend's place, so I wasn't around much. When I got home, he seemed a bit off, but I didn't think much of it. Went to my office room to have a video call with my boyfriend. Night went by, I sent him a meme in the morning as I do every now and then. He asked if I had a good night, I said yes and apologised for not being around to hang out. He said it was cool and that he wasn't doing well, so it was probably for the best.
Asked my partner about what was up with him, and he mentioned that he's dealing with some jealousy about me and my boyfriend. So now my brain is just going like, wtf, he has no right to be jealous. He squandered anything real happening between us. And I'm better off without that hold he had over me. Now I have this useless information that my former LO is jealous of... someone else getting what he could have gotten, I guess?