I’ll start.
We had great chemistry but different goals. She was religious and looking to marry and thought she could change me, a non-religious person who intends to remain unmarried and childless. I was up front about the lack of religion and the lack of desire for marriage. She was not up front about her intent to change me.
After two months of regular flings she told me we couldn’t see each other anymore, because she wanted someone to go to church with, it was my fault she was living a sinful life (totally), and she was cheating on me with another dude was a Christian.
We were polyamorous, had spent 8 years together, and then her other (new) partner decided she didn’t like me. So she put a wedge into our relationship by breaking the trust down between me and my partner, framing me as abusive, and eventually my partner abandoned me after the trust was gone.
The other gal turned everything I did into some manipulative scheme or way to control my partners. For example, the fact that I couldn’t suddenly drop $2k on a wisdom tooth removal for her became “financial abuse and control”.
I’m going to be angry about it for the rest of my life, I think.