Was in a on-off relationship with a girl when we were both around 18. We would be together, then break up and try to stay friends, get back together, just to break up and not talk for a couple months, all across 2-3 years. All in all very unhealthy but just normal teenager stuff until that point. When we ended it the last time we really tried to stay friends because we were so close and still hung out nearly every day. She started asking me for money often and I gave it to her, because both of our families are pretty well off and I knew I could get it back from her parents any time. She took a pretty big hit when she had to accept that she would never be a doctor and started going out more. One day she tells me she fell in love with a 10 year older woman and they are together. Didn't see that one coming, but tried to be supportive because I knew she had a hard time. She changed completly, went batshit crazy because of that woman, until the point I couldn't take it anymore. Went to her parents to get my money and leave, but her mom, who always liked me, wanted to talk to me. Turns out she had lied to everybody in her live for years. She had cheated on me while on holidays with her parents (which we realized when we compared stories), just generaly manipulated everybody, but was in control of her lies until she met that woman and went crazy. Additionally we figured out that she needed the money from me because she had an eating disorder, where she would eat just tons of food just to vomit it out immediatly. She managed to hide it from me for more than a year (I realized the signs when I knew it, but at the time I didn't have an idea). Only heard from her once after that before she talked to her mom. She moved out shortly after that and her mom called me a few times to ask me if I heard anything about her, because she moved in with that woman and just broke off every contact.