DaveJ, my advice would be not to cal the MIL. Woops to late for that. The MIL is your W's support group. You are invading her space and accessing her allies and comes across as manipulation on your part. I know that would not go over well with my W.
The C could be touchy. If you wife did not know then I say go for it (see reason above). She would be able to maybe offer you some much needed advice, but it could back fire on you.
“Do you want to be RIGHT or want to be LOVED” “You have to have a life to share a life with someone” “When you stop resisting, you start learning”