I need advice FROM GUYS ha?

I met this guy last semester and we really hit it off! We IM all the time sometimes even til 4 in the morning. A few months later I found out he had a girlfriend. I stopped most flirtation and tried to just be friends. But that's really hard. So I finally told him I wished he didn't have a gf and that i liked him. Since then we have talked about her a few times and he used to seem really happy with her and I let it be but now she seems to like him more than he likes her. The other day he texted me asking me to hangout and I went. Nothing big, and NOTHING HAPPENED. but now I like him more than ever, but i don't know what to do. I know wanting him is wrong. but I honestly can't help it. Should I pursue it more? if so how? or should I just try to drop ties completely?