I see your point about you allowing yourself to be vulnerable by sharing with your H things that have hurt you. That feeling of vulnerability would be exponentially increased, I would think, by knowing that he's going to share it in a group.

I think it's really important for your H not to share with you the things he talks about in group that involve you. I don't think you should know that he has talked about you in group or what he has said. I think you need a really strong boundary if you're going to share these things with him. That he does not come back to you and share things that the other group has said about your reveal, or he does not come back and share with you that he even shared these things that you said.

I think that by him sharing these things, he's creating sort of a triangulated conversation between him, his group and/or his T, and you. It's fine for him to share directly with you HIS thoughts and feelings-- e.g. if he were to say, "today in group I talked about how badly I feel for how much I have hurt you", that seems un-triangulated. But if he were to say "today in group I talked about how badly you must feel because of my addiction and Bill said that you were obviously a strong woman and didn't need my pity." Or T said this about you, or whatever. I don't think it's helpful to you to know what others have said about you and how you feel. What your H feels about how he's hurt you, fine.

I don't know if this makes any sense. But I'm the person in therapy in my marriage and I talk a lot about my husband and my marriage. But I do not tell him anything about what I talk about in T, and it feels to me that if I did, it would have overtones of "my T thinks that you don't support me enough" and a few other issues. I think that what one person chooses to pass on to the spouse about his or her own therapy process should be strictly limited to sharing about what he has learned about himself and how he wants your marriage to be different. IMO only.