So my current boyfriend and I met in college , but I was dating someone else at the time and he was still with THE EX. A year after we graduated he called me out of the blue and asked me out. We started dating immediately, and things were going really well. I knew he was still friends with his ex, and I was totally cool with that. They shared all the same friends so I knew they would be in contact somehow. About six months into our relationship he went on a trip with THE EX and a few of their other friends for two weeks. I wasn't really worried, but about a week into his trip I still hadn't heard from him. When he got back from the trip everything went back to normal, and we were fine (or so I thought). Suddenly, I noticed that THE EX was calling him a lot, and he seemed to have to fight with her in every phone call. Finally, I got his phone and read his texts from her. She was begging him to call her back, saying that she loved him, yada yada yada. I confronted him and he said that while;e he was on the trip she had told him she still loved him, and he was feeling "confused". I was pissed and we fought, but at the end of the argument he agreed that he wanted to be with me and that he would tell her to back off.
Even though he told her to back off THE EX still called about four times a day, telling him she loved him in texts blah blah blah. She was living across the country at this point. Finally one day, when he had forgotten his phone at home (we were living together at this point), I answered her call. She said "I need to speak to him. It's an emergency about my family!" I said I would gladly take a message and let him know, but she insisted she needed to talk to him and not me. I finally told her the deal. I said "you need to stop this. We are living together, and you are being ridiculous." She replied that she and my boyfriend were "like family" and that no matter what I would never be able to take him away from her. We fought on the phone for an hour, when she finally said that she would stop calling and would leave us alone. I told my boyfriend what she had said, and he said he felt bad.
A few month later the calls/texts started again. One read "don't worry I told (me) that I'm OK with your relationship, so we can pretend to be just friends". I was pissed and told him I saw the text. He said he understood, but that she was still in love with him. I few days later I fond out through friend that THE EX quit her job, got in her car and drove the 35 hour drive cross country to come and "get" my boyfriend to go with her. He evidently choose not to go, because he was still at our place when I got home, though he was looking very sketchy. He told me we had to talk, and said that during their trip he had slept with THE EX, and that if I really wanted to be with him still, I needed to know that. I was heartbroken, but for some reason decided to stay with him. I told him that I still wanted to be with him, but if we were going to be together I could not stand for him to have any relationship with her. He agreed. THE EX went back to where she came from. I still felt so much hate towards her, she was way prettier and skinnier than me, and she seemed to have no shame (which I evidently have a lot of). To be honest, I was jealous of her in some way.
A few more months later the boyfriend and I decided to move to New York to go to graduate school. I had heard that THE EX was living there, but I figured "hey, it's a big city, I can avoid her". No such luck. The day after I moved into my new place, I got an email from THE EX, essentially telling me that she needed my boyfriend in her life even if it was just as a friend, and asked me to PLEASE LET THEM BE FRIENDS!!! I wrote he back a scathing email, saying that I had had no problem with their friendship when he and I first started dating, but since she decided to try and break up our relationship I had no need for her in my life. I also told her that my boyfriend was free to be friends with whomever he wanted, but that I had told him I would no longer be his girlfriend if he were friends with her. She wrote back stating that I was being mean, and that I was breaking up their "family" by making this rule.
So that's about it. She still trys to contact him every once in a while, but she has a new boyfriend now so I'm not too worried.