Ok, so my ex girlfriend and I were together off and on for four years, and each time we broke up it was on very bad terms. We did this back and forth forever and finally just stayed broke up. Then, a few months go by, she calls/texts me out of the blue saying how much she misses me and loves me and wants to see me. So like a fool every time I hang out with her every time she wants and then we end up getting drunk and usually having sex. Then a week later I'm talking to a friend bragging about banging my ex (you know how guys do) and he's like really? Shes dating so and so. Oops? Months later same thing happens, only she's dating a different guy. This has happened multiple times over the years and she keeps cheating on her boyfriends with me. What do I do? And what's the issue here? I'm lost