My ex sounds very much like yours... it takes a long time to get over a relationship like that! I know I would also feel the same if my ex moved back to the area I live in and started seeing someone. But you know what.. I think it is also best to leave it. I dont think she would believe you, new love is blinding and it would create far more problems for you and your family than its worth. I was told when I started seeing my ex and I saw plenty of signs but chose to ignore them!

I will admit I do still google / fb my ex every so often to see where he is.. I know I shouldnt but it sometimes get the best of me and I have to check. I also feel better knowing he is no where near me!