Should I try to forget about him?

About 7 months ago, I was dumped by one of the most amazing guys I’ve ever met. I was so in love with him and he had given me my 1st kiss. After we broke up, we didn’t talk for the rest of the school year. After school had ended, he switched to a different school. After many months of crying over him, I began to fall for another guy and lost interest in my ex boyfriend. My ex boyfriend had gotten a girlfriend anyways, so I realized it was time to move on. My boyfriend and I are very happy. He is really good to me and I have a lot of fun when I’m with him. I had finally gotten over my ex. Then, the other day I attended my friend’s birthday party. At the party was my ex boyfriend. That was the 1st time I had seen him in 7 months. I was overwhelmed. Everything that we used to be hit me like an extreme train wreck. I couldn’t bear to look at him for more than a second without getting tears in my eyes. He had put me through so much pain. We said hey to each other and the moment I his sweet voice, BOOM! I liked him again. Once the party was over, I went home and cried. My ex boyfriend and I talk on aim, and I wanted to tell him I liked him again.. infact, I almost did but I didn’t. I just didn’t want to seem easy. I told my parents about it and they’re highly encouraging me to stop talking to him on aim or any other way if I wanted to forget him. But a couple days ago he told me he was going to this concert.. I had already planned on going to this concert so I will definitely be running into him there. Part of me wants to see him again, im just so in love with him. But another part of me doesn’t want to because every time I see him I fall for him more and more. Infact, I think I like him more than my own boyfriend.. but I know for a fact he’s lost all feelings for me because he has a girlfriend that he really likes and she lives right next door to him so I have a feelings they’re going to last a while. I just feel so guilty and alone. Am I being a bad girlfriend because I like another guy I want to talk to my boyfriend about it but im scared he’ll dump me and them I’ll have nobody. Please don’t reply to this saying something like “well if you’re happy with your boyfriend then just forget about the other guy…” or something like that. I can’t forget about my ex boyfriend. Only time can heal that. But part of me doesn’t want to forget about him. What should I do? I tried to explain all of this as clearly as I could so I hope it all makes sense. Thanks to those who reply, you guys’ opinions will determine one of the biggest choices of my life right now.