What’s the worst thing your ex has ever done to you?

I’ll go first!
When we were together he told his friends that he would’ve dated my sister and not me. After we broke up he dated one of my friends and we all had the same friend group so I still talked to him normally. But when I started dating his one of his friend, he left the group until I broke up with his friend and now he was dating my ex bsf (⌒▽⌒)
lowkey not bad but he’s petty asf…