I feel like talking about this for some reason. It's sort of on-topic but it's not really got any point to it except me venting.
When I was 17, I started dating my first boyfriend. He was a long-time neighbour and friend of my BFF. At the point when we started to get close, another mutual friend of both of these people started getting close to me.
She looked COOL. I'll say that now. I was always jealous of how pretty she was in her alternative and conventional ways.
I was just glad to have another friend who was as keen to get to know me as she was. I actually felt sorry for her because she had such a bad past and she lived in a shitty house/location and stuff, so I would try and encourage her about the good things that happened in her life as often as I could. I knew that she had a brief and very strange history with my at-the-time boyfriend but I didn't let it bother me. I did get jealous though and wanted to ask him so many times to not hang out with her any more. But I was too shy.
So we broke up for other reasons, and things were OK. I got a message one day from my BFF saying that this other girl was saying she cheated with my guy right after me and him first... ya know. For the record, this could easily be the truth, but it could also be bullshit because both of them are just as huge liars as each other. As people do in that situation, both person said THEY were telling the truth.
But this girl did a COMPLETE 180 on me and all of a sudden, I was her worst enemy. It was so fucking weird. For months afterwards, she would send me death threats and say shit about the fact that I went to a private school (which I never even mentioned, I only ever said on occasion that I had to get back home and do homework) which seemed to REALLY rub her the wrong way.
It was so obvious that I had the life she wanted (I got along with my parents for one thing) so for a while I would just rub it in her face, it was quite funny. But after I blocked her on everything and she stopped trying to add me back on Facebook, it was clear her life was just out of control and a total mess. It wasn't fun any more to gloat on how much better mine was, so I just left it at that and forgave her, because I wanted to be the better person.