Processing my Ex remarrying to my least favorite person on earth is really fucking difficult

So I’ve been separated 2 years divorced about 18 months, from a wife of 13 years. She left me for the karaoke DJ that used to host at the local bar (he has a steady job now though). They conspired to first siphon money away from me while she pretended to still be in love and then later spread rumors that I was abusive that fortunately didn’t stick but strained all my local friendships and lost me a few friends who “always believe women”… I don’t blame them for that but it sucks when there are actual false accusations… including calling the cops on me. Her new man actually got the idea because it happened to him with his ex gf so that makes me despise him way beyond what is typical… especially putting my kid through all that.

Anyway… Throughout the time since the divorce my ex has been begging to get back together and I’ve told her that would only happen if she could become independent because I would never share finances or a lease with her ever again after that. She made it seem really likely she would stick with it which is a win-win for me because even if she didn’t get back together, she’d at least not be with this asshole. She even hooked up with me a few times and sent a lot of sexual images and videos of herself with my name explicitly stated in them. She was essentially cheating with me the whole time she was with this other guy.

About a month ago the guy gave an ultimatum: marry me by the end of October or get out. She wasn’t anywhere near ready to be on her own and I have no intention of taking her back as a dependent if even at all. Now that she has “made her decision” she’s behaving completely differently. Blaming me for things her current man is doing (like not allowing her to use her full visitation time), throwing out all our happy memories and boiling me down to a few heated arguments, demanding adjustments to the custody time that are obviously her wedding activities but painting them as time for our son to spend with his aging grandparents so I would look like an asshole to refuse.

The latest one was a doozie though. My son was invited to a birthday party… I asked her to please drop him off there at the end of her custody time cause I would be there for the party too and it made sense as a convenient swap point. She knows the birthday boy’s mom and asked if she could come inside and say hi before leaving and I said sure. When I arrive she and her fiancé are fully trying to attend the party. He doesn’t know anybody there and neither of them were invited and I was the one who purchased and brought the gift from my son. She goes around introducing herself and him to people and I did what my lawyer said I should do and just kept my mouth shut but I was fuming and everyone in the room who knows us knew exactly what she was doing to try to provoke and ambush me.

It all happened so fast and then she said they were going to go cause I was “making them uncomfortable”… I think because she had no reaction to point to of me losing control so she went with “bad vibes”. It is just so disgusting that she’s parading herself around like a loyal monogamous future wife of this guy who was a complete asshole to me while I have 18 months of fresh sexts, images and videos of her (and some of us both together) on my phone that would likely end their relationship. But I can’t show them because that would be illegal under revenge porn laws and further derail what was supposed to be a kid’s birthday and not her stage to start drama. I still feel sick to my stomach thinking about them cause not only did they spring this on everybody without warning… but they’ve both glowed up for the wedding and I know I have deteriorated and gotten fat from the stress of single dadding on top of a full time job and lots of volunteering and other stuff to keep me from rotting in my apartment all the time. It’s infuriating shouldering all the responsibility and watching them have all the fun while claiming they should have my son more despite skipping visitation days. I can’t stand knowing I likely get to look forward to 5 years of them continuing to thrive in a no-kid existence as I bleed out my health and money doing the right and responsible thing… that is if they don’t successfully take custody from me.

I can deal with losing her, I can heal from what she put me through, but the hypocrisy and social manipulation is exhausting and I feel like I can’t do anything about it because she will always find new ways to needle me… even using our son and his friends as a battleground but always with plausible deniability if accused.

The party went fine after that and the host apologized saying she had no idea he would be coming in and that it was awkward and confusing for more than just me so… that’s good. The rest makes me wish I had done something to stand up for myself.