What is wrong with me ?

Okay so there's this guy who's like a really good friend of mine and we do a lot together. Let me start off by saying he has a girlfriend and cheats on her with other girls, and he also still has a close attachment with his ex(He says he's in love with her but it's just the sex) Recently last weekend we had a sexual encounter... we were doing thizz together(Yeah i'm a druggie **** happens get over it) and we both got super horny my chick best friend was there also. Me and him were all over each other started making out and got a little touchy feely, my clothes came off... My chick friend was annoying and drunk and she was left out so he felt bad and had her join in. I then got super pissed and said he was taking advantage of me and put my clothes back on and left. By this time I was pretty much sober, He came after me and told me that I know I wouldn't be just a one night stand on thizz he kissed me really romantically and we made out before I got in my car he kept looking me in my eyes and hugging me. He told me he didn't want to hurt me and that he was so sorry. Him and my friend had sex. I was so aggravated, and he told me that he didn't want to, he felt bad that she was coming onto him and he was really ****** up he couldn't just stop it, that he really wanted me. We confessed to each other we had feelings for each other. Nonsober sayings are sober thoughts! He asked me why I hadn't told him how I felt before. I told him that I didn't really know what I was feeling I was really ****** up and I am not a slut and am not going to be played by him because I know his game. Yet I really do want to hook up with him I know it is not right. But the heart wants what the heart wants :(