He said he is willing to breakup with his girlfriend to be with me

I know this guy since I was in highschool, his name is A. When I know him, I had a boyfriend, G. I really like A that time but I was with G and I didn’t know that A was feeling the same way as I did towards him. When we graduated from highschool, A told me about his feeling through sms and he wanted me to break up with my boyfriend. I was about to break up with my boyfriend and I received a msg from A saying that he was with a friend and his friend just broke up with his girlfriend and luckily he didn’t have any girlfriend. This make me assume that A was joking when he wanted me to break up with my boyfriend and he was joking about his feeling towards me. So I didn’t break up with my boyfriend, but after 3 months of the graduation date, we broke up.

Now, after 4 years, I was chatting with A again through msn and he told me about his feeling and how he felt hurt because I didn’t break up with my boyfriend and he thinks that I cheated his feeling (which obviously, I don’t think I did). He told me that if I am willing to love him, he will breakup with his girlfriend and be with me. We haven’t met for 4 years. Do you think I should believe him? What do you think I should do? I still like him a lot, my feeling towards him have no changed ever since then. I don’t want to get hurt anymore and I find it hard to believe him because he keeps on blaming me for hurting him in the past and I can feel hatred in him towards me.