I am also I jealous person it is hard but that is where trust comes in... the key words your boyfriend said while talking to his exgirlfriends mother was, "I love her but WE ARE DONE..." I love parts of my ex yes because there had to have been something to love to begin with but I am in love with my current... To me that is a big difference. I think if you promised your boyfriend you would work on your jealousy then that's what you should do... and realize if he could have gotten together with his ex along time ago and hasn't and from what I read it seems as if it is never going to... So just think about all the variables before becoming so jealous. It's hard not to become jealous I know still working on it everyday...