Many kind regards, Steppingup.
In terms of what to ask your WS--well, I'm a firm believer that any or all questions you have deserve a full, transparent response.
I would want, therefore, to be sure that I did not choose an MC whose approach to recovery from infidelity erected any barriers to this.
Unfortunately, there are rugsweepers among MCs, just as there are among the rest of us. My questions would be geared toward identifying these and weeding them out.
I wouldn't even do MC if she is still with the dude. We did ours a week after dday and she was still completely in la la land.
The most important questions at the outset, IMO, are those posed to the MC: what is your experience with infidelity? What is your approach to guiding a couple post-infidelity? Etc.
Our MC was not familiar with the books "How to Help Your Spouse Heal" and "Not Just Friends". I used a lot of info and advice that I got from this site, both from The Healing Library and the members, to have "talking points" at our sessions.
I LIKED our MC - and we will probably return to him after WH gets to a certain stage in IC. I quit MC after DDay 2.
There are few counselors in our area. We have to drive an hour to see one. Our first MC was a waste of money!
Good luck to you!
What you need to do is really be honest. If the MC is any good, some of the questions the MC will ask you will be uncomfortable. Resist the urge to gloss over or dodge any questions.