Emo Scene Community

Ok, so a few months ago, it was completely unplanned, but me and my best friend fell in love, we'll call him John, we didnt come out properly as a couple, but everyone knew we were crazy about each other, he was mine and i was his. Then, i made the biggest mistake of my miserable life :( I had just gotten back from my holidays and my other best friend (another guy, we'll call him Mark) told me that he had seen John cheating on me :( Blinded be grief and hurt, i told John i never wanted to talk to him or see him again, i was just so upset :( I then went away for another month so it was easy not to have the temptation of seeing him, and when i got back, i was prepared for the possibility of seeing him in town. About a month ago now, me and mark mended the broken bridges and are back to being best friends. He now has a new girlfriend. I am heartbroken. And the worst part is, my friend Mark who told me what john did, was lying! John had never cheated on me or ever done anything wrong, i made the biggest mistake of my life by listening to Mark, who did it because he thought that MAYBE John might hurt me someday. Now, the current dilema is that he has a new girlfriend, but he tells me he still loves me and he misses me, and the other day, when he had a free house, he invited me over. I couldnt go anyway, but now i dont know what to do. I am still in love with john but he has a girfriend, and i dont want to be that girl whos the whore who stole another girls boyfriend, but i also feel really guilty, i mean the poor girl like, her boyfriend is in love with someone else :/ What should i do?????