I wouldn't tell my in laws with the intention of getting them to try to stop the D. The D is happening and frankly I don't know that I want to stop it at this point. The betrayal (and I don't mean just the betrayal of the EAs, but all the other stuff too) has eroded my love and ruined any trust and I don't know that we could ever re-build a good relationship with those issues.
I'm sure almost everyone here has gone through or will go through the retribution phase and my fantasy of exposing her to her family is part of that. I'm human and I feel that everything needs to be fair, so why does she get to tell her family and friends "part" of the story - the part where I'm sure I sound like an a-hole. Shouldn't they know all sides of it?