I am in a fairly new relationship with a wonderful guy. We have been dating for two months now, and I can't help but feel jealous, wonder about his exes, and I am constantly resisting the urge to check his cell phone for messages from them, and other similar moves. I know that kind of thing is bad news, as I have already lost one relationship over that, and I desperately want that to never happen again, and not with this guy, who is truly sweet and caring. Do you have any advice for me?