I'll go first. My ex cheated on me with a dude, (I'm les, she's bi,) brought home chlamydia and bed bugs, then after 13 years of no contact, texts me randomly to try and pull me into an MLM pyramid scheme.
I've only had amicable breakups (37, male, single), except for this one: when I was still figuring things out in eighth grade, a girl that I had broken up with threatened to pour coke on me - which she was holding in her hand - which made me miss a final exam and the teacher wouldn't have it so I failed the class. Dafuq.
Just realized your question was about exes trying to come back to our lives. Never mind.