My husband was honest with me (brutally honest sometimes). The whole thing hurt like hell. BUT even when I would get upset and cry, after I had the questions answered (whether it hurt or not) I seemed to be able to calm the obsessing and really examine the answer and make some peace with it. Sometimes they would lead to more questions, sometimes I could finally let whatever was rolling around in my head go.
It helped my husband, and made him a little more willing to answer the questions, to know that even when I was asking the questions and hurting,on the other side of the pain of the answer, there would be some healing for me.
He got frustrated, because my questions would point out how truly disastrous his decisions were, and how selfish the A was.
Good luck with MC - I have found mine is invaluable (and by the way-so does my husband).
((broken)) Hope everything works out the way it should for you.