I really think you're self conscious when he sees a blonde woman. I used to get like that when i would think my boyfriend would look at prettier girl than me and we almost broke up too but then I realized that I really needed to trust him because I just wanted to have a good time with him and not worry about other girls I really think its the fact that his ex was blonde really gets to you if she was a brunette then maybe it would have been a different story I really think you should try to work things out with him and everything will OK! dont bring the past into your future!*