Listen......

So let me start off by saying that I'm bi and my last girlfriend and I did not work out although she pleaded for me to reconsider but I didn't so we slowly became friends and I started dating someone else I introduced them to each other and they slowly became friends because they shared the same love for music and the guy I was dating at the time was the type of guy who thought it was okay to date more than one girl at once so he had both of us but he started to neglecting me, and his good friend studies showing attention to me we hooked up and it got worse and worse for my boyfriend and I and finally we broke up so now my ex girlfriend who is still with him they are engaged now thanks its ok that we're friends for her birthday just passed and we were going to hang out but we ended up not hanging out and it really kind of bothers me because I don't have many friends a very small circle of girlfriends I don't know what do you guys think ? Do you still it's okay for two ex's to date do you think it's okay that her and I remain friends or should I say forget her for what she did and move on?