Your MC and IC should not be the same person.
Is your MC your only therapist in town?
If not, then your H needs to interview therapists to see how they feel about porn before finding a new one.
If HE wants a therapist that will work with behavior modifications w/r/t your husband watching porn, then I probably would look for a CSAT.
Finally, I think you need to decide how big of a dealbreaker the porn is. It could be very likely that if watching porn is a 40-some year old habit for your h, he's not going to be able to stop simply to please you. He's going to need to WANT to stop because HE wants to.
I would consider things like only getting on the computer in your presence, or getting NetNanny for your computer, or him vowing he's going to read a book, go for a jog, or do a crossword instead of watching porn to be indications that he wants to stop. I would also consider him looking at places like no-porn.com (or maybe net, I'm not sure anymore,) recovoerynation.com, or reading "Every Man's Battle" to be indications he wants to stop.
ETA: Normal therapists have NO understanding of porn watching that can't be stopped. My husband is a recovering SA, acting out with porn and compulsive masturbation. One therapist I saw told me that my husband could watch porn, even though he's addicted to it. That's like telling a heroin addict it's OK to get high on the weekends, but not during the week.
So, you need to be careful. If this is a big issue in your marriage, your husband getting the right kind of help is imperative.