Does this mean we are meant to be together? Please HELP!!?

My ex- boyfriend left me 1 and half years ago for another girl. About 9 months ago he tried getting back in contact with me but I refused to talk to him because I still had feelings for him ( I still do) and I didn't want to make things complicated. He kept sending me cards and emails every once in a while telling me he had something important to tell me. Well, I ran into him the other day and he we started talking. It was really nice and I could tell that we still have a connection like we did when we were dating. (We dated for 4 years). Anyways, he all of a sudden told me he still loved me and didn't know why he broke up with me. He said he was really confused at the time and he should have never left. He would come back to me now but he doesn't want to hurt the girl he is with just like he hurt me to be with her. Should I believe that he really loves me? If he leaves this girl should I date him again? Even though I love him, do you think it would be possible to trust him?