The fact that you aren't even sure if they are back together (did he give you a reason to think that, or are you creating that situation in your own head) should tell you that you are spending way too much time on someone that you aren't with. Have you been to an Al-Anon meeting lately? You can't control situations that are out of your control. If they are back together, then there is nothing you can do about that. If you run into him, there is nothing you can do about that either short of moving out of your town. If you need to do that, then maybe you should look into those steps. At least you will be taking control of the situation instead of letting it control you. I hope you find peace with this situation. As far as your parents' home for the next week? If you really feel you need to do that to keep your peace of mind, then do it. But just remember that you can't avoid the situation forever and eventually you will have to face your fears. Just do it one day at a time.
Jenny