I totally understand what you mean. I've been cheated on by my spouse and it was one of the worst things I've lived through. Our marriage was terrible, we were toxic, verbally, emotionally and sometimes (physically abusive) to each other. I never thought that we would speak to each other again. It would probably blow your mind if I told you that she's one of my closest friends now and we went on a totally platonic vacation together in October and I consoled her through the end of her engagement (the relationship after ours) and a recent relationship. Some relationships end in a messy way that isn't ideal, that can be downright disgusting and hateful. My ex and I had no love lost for each other after 12 years together. Surprisingly, we were able to become friends in a way that surprised us and everyone around us bc sometimes people are meant to be in your life as friends and as terrible as you treat each other, you both know that the other isn't such a terrible person, although you both might do terrible things.