I would write a letter to the clinic explaining that she has no business working with your H on his marriage without the proper training and by excluding you.
This will kick into gear two things :
a. She has the training and will invite you to MC.. which she can't do if she's treating him for IC b. She will NOT get involved with the MC at all with him and will reccomend he speak with a MC of her reference.
She can't do a, and she likely isn't trained in that topic... the thing is... she should be TELLING your husband that rather than NOT SAYING anything.. she has somehow left HIM with the impression that SHE is qualified to help him work on his marriage... SHE needs to clear that up. And you as his wife are entitled to approach that business and CLEAR that up.. OR demand in invitation to the sesions... the idea that a MC treats a marriage with just one spouse in secret and not even contacting the other who is possibly willing to attend is unprofessional.
So, I would confront the clinic and tell her
a. Straighten H out that she is NOT qualified to discusss the marraige at all OR b. Invite you to the sessions if she IS
She cannot professionaly practice as she is now in my opinion... if she's discussing the marriage at all, she's crossing a line and you have every right to confront her on that
