Why do you get jealous of your boyfriends past crushes?

Well, its either that you are comparing yourself to them and feel insecure or you are just not ready to have a relationship yet. Maturity is a big part of a relationship and you cant have any anamosity towards his past because you werent a part of it, maybe, that is one of the problems too but you cant to do anything about that and if you continue to sabotage your relationship because of his past "crushes" you will lose him. Start focusing on your today and tommorrow with him and be happy.