I still believe you have to walk a fine line with this. Not having any expectations also means not giving any. Your W wanted this, and although on the outside it may look like the best thing for your S, it's not. Especially at his age, it may cause more confusion than anything. He may end up having an expectation of Mommy and Daddy working together and it may hurt him more in the long run if it doesn't. I know that is not something you want to think about, but it is a possibility and you have to be prepared.
Im still standin better than I ever did looking like a true survivor feeling like a little kid Im still standin after all this time and Im picking up the pieces of my life without you on my mind..