Truly, I wouldn't bother contacting the in-laws. I know it might feel tempting, but with time the truth will seep out anyway and you won't be the 'bad guy' for letting others know what was happening.
My XH didn't tell his parents for ages and they were pretty cold with me. In the end I told him - Please can you tell your parents what has happened here. I don't expect do feel censure from them in this situation. And he did then tell them.
You could always take that kind of approach. Just be sure when acting that you are doing things from your 'higher self' and taking a long term view. If we act in haste and in hurt we can come to regret things in the longer term.
I'm glad to see Sandi posting on your thread - she is a wise woman indeed.
Take care my friend
Thanks sotto... Those are the choices I'm weighing right now... perhaps to hasten the decent and turnaround not to R but to heal and able to trust again -as a co- parent not a wife. But I'm afraid the bad choices and spiral downward is accelerating and nothing I can do about it. Nobody see this but me.... For now...
Me:47 XW 43 D15 D10 Together 17 married 15 Bd : Mother's Day 2015 Sep :July 2015 Divorce final October 2016