My first boyfriend faked a serious amputation accident after we had broken up, I believed him, and then after he was banned from the social media website for "threatening other users with death"; he explained that our entire 1-year relationship had been just one big social experiment to see how he could manipulate people like me into believing him.

I had a boyfriend in a gay relationship that was online / long-distance, and it ended with him describing our 1-year time together as a social experiment and complete ploy to see how he could manipulate someone younger than him to be his boyfriend. This explanation was after a complete shit-storm that went down on a social media site where he claimed that his hand was severed by a fallen replica display axe that fell because "he punched his bedroom wall so hard that he broke parts of his hand and loosened a support beam", and then caused the axe to cut into his wrist. But within three days of said "accident", he'd written this largely descriptive explanation online of how he had become hospitalized, and how it was MY FAULT for his supposed accident, all because of my breaking up with him. For a long time he'd been overly abusive to me, acted horribly racist online whenever he was killed in competitive gaming, and acted like a neo-Nazi to online players via headset mic as he described how badly he wanted to "incinerate and cremate Jewish people and finish what Hitler started" to the people that had just recently killed him in-game on Xbox Live matches... Seriously, he was a total psycho and I am so glad to be rid of him. He wasn't a good choice for a first boyfriend, but thankfully my love life has drastically changed since then, and things are going much, much better now.