Am I over my ex?

Well, the fact that it's been 3 years since you've been with this guy shows that there was a strong bond between the two of you, and that might explain why now it'd bother you to see him with another female. My suggestion to you, is to go on and forget about it. yes its easier said then done, but it does help. why not go out with friends, meet new guys, have fun. Keep your schedule busy and as well as your mind. Acceptance is a long run but soon you'l realize there's nothing to change what has become. And it won't bother you anymore, and you'll be glad your not in their position. There was a reason for the break up, and don't forget it. It's a phase that you're going… But if it seems to bother a lot and it gets more intense, the problem may be deeper then an ex from 3 years ago. You might want to talk things out with a trusted relative or friend.