What Tania M said may be true for some girls, it certainly isn't for all. I would never keep an ex around as a back-up - I have too much respect for my relationship with my boyfriend. Even if my boyfriend and I broke up, I wouldn't date them again. I have absolutely no interest in two of my exes that I've remained friends with, and they have no interest in me. We dated a long time ago, broke up, and realized that we really enjoyed being apart of each other's lives, but ONLY as friends. I don't talk to my exes everyday or anything - I talk to them once in a while, as I do most of my girlfriends that I cannot see everyday at work. While everyone has insecurities, I am friends with my exes because they are good guys, not because I'm using them as back ups. It is rare to find true guy friends that you can trust. I trust them, they've been good friends for years now.