Oh man.
I had a boy in grade school, at a school I only attended a few months, not a boyfriend, but he did me mean. Years later, we ended up stationed at the same base. I arranged for some Marines to beat him up.
I thought I had the winner until I clicked on your link!!! Back around 1975–1977, I worked with a girl who was wound pretty tight. Her bf was cheating on her daily. She got tired of it & told him that the very next time he cheated that she was gonna turn him into a girl. He cheated, she cut off his penis & then threw it out the door for a treat for their dogs. She never called 911 & he bled to death & as far as I know, she’s still in jail.