What should I do, ladies and guys I need advice...?

So I met this guy about 4 years ago at work while I was in college. We would chat through interoffice mail practically all day. But I could tell he was shy and never had the courage to ask me on a date. Then I moved away and we just kept chatting online and through text. After about the 2nd year of us just chatting at least once a week, he came to the town I live in for a work conference. We both were and are involved with someone but we decided to meet up anyway. Well he ended up getting stuck in some meeting and we never met up. I felt like it was an excuse because he was so shy about meeting up with me. So i completely cut him off. We didn't talk for a year. He would try to contact me, but i could just ignore him. I thought about him often and missed our conversations. So i decided to contact him again. We have been chatting everyday all the time for the past few months and met up about a month ago and we could tell there was a major attraction but nothing happened. After that he kept saying why didn't it get physical between us...blah blah I want you, I want to kiss you next time we meet up. So we meet again this past weekend and things got physical, and it felt right. That night we both expressed how much we enjoyed finally being with eachother (not sex, everyhting but). The next day he said he felt guilty because of the his GF and didn't think we should do anything else. What did he expect to happen when he invited me to go home with him. He talked so much about missing me and how much he liked me. I am so confused, he has led me on for so long and then when it came down to it, was like things all the sudden got to complicated. i still have strong feelings for him...What should I do? :-(What should I do, ladies and guys I need advice...?
i think it's his issue. i don't think he lead you on (not on purpose) cuz it seems to me he is shy or a bit awkward. he obviously likes you and i think he still does. i am split on saying whether you should just drop him, keep him at arms length, or tell him how you feel. i almost want to say you should tell him but he may bring up his girlfriend and some bs excuse like he just wanted to kiss you for a long time and that's why he did it but he has a gf and loves her very much. I almost want to say just to stay friends with him just in case something changes which sounds like something could.