Whatever the reason, try to work it out, learn to forgive and forget..start anew. That is, if you still love each other and your family. If love is gone, it's gone...you will just be unfair to yourself and to your family and you won't be happy living pretending that everything is alright. There were couples who managed to part ways but keep their focus on their child. Well, it depends, whether you want to save your relationship or not. Then you can decide on what to do next..just make sure that the kids don't suffer. Do what will make you happy and be ready for the consequences.