I'm trying to think of all the various things that have been working...
H read both DR and a book called "After the Affair". Both describe in great detail the effect that having an A affects your partner. That helped H to see that what I was going through was pretty typical. Both books relate that the betrayed partner will have lots of questions and want to talk about the A and that the unfaithful spouse should be forthcoming and accountable. That helped H see that my requests are not unreasonable.
I think (big generalization here) that men often compartmentalize parts of their lives and parts of their relationships. To me, the concept of sex with someone I don't know or someone I don't like or care about is unthinkable. To my H, as with many men, he was able to compartmentalize and rationalize that his A was with brief and with someone he didn't care about. I'm learning that (statistically) many men who have affairs aren't even necessarily unhappy at home and do love thier wives (how the hell do they DO THAT???)
He's learning that women (generally) think in a more integrated way (tip the domino down way over there and it sets up a chain reaction). To me, his A affected and degraded everything. The betrayal and specific memories of dates and times he snuck around and lied will stay with me for a long time. I let him know things like how every year, on his birthday, I will have to live with the memory of where he was on his 48th, and that he smiled and lied in my face about it. H recently said he thought we would have to do something symbolic on that day every year--for both of our benefit.
When we do talk about the A, I try to make sure it comes before and after constructive talks about our relationship (sandwich it in between good stuff). I tell him that I want to hear his "story" and that I need a better understanding of what went wrong. He tells me as much as he is able to, and I may ask a few questions but not push too much. I ask at certain points what he would have done differently now. Then I will say, "next time we talk, I'd like more information about..." and tell him what I'd like more detail about. That way, he doesn't feel blindsided and has some time to really think about what I'm asking. I've also let him know that it's much better to give me information than to leave big blanks for me to fill in with my imagination!
It's very hard for me to keep my composure during some of these conversations, but I try to remember to be compassionate. I can honestly see that H has caused himself a great deal of hurt and shame and is truly remorseful.
I have tried to avoid asking a lot of questions about specific sexual activity with OW. That wouldn't be terribly productive for me to hear about.
Where we are now in the ongoing discussions is focused on dishonesty and betrayal. I've told H that it's very hard for me to deal with knowing that my partner, my best friend, a man who made promises of fidelity had lied in my face repeatedly. Knowing that, it's hard to want to try again and believe anything he may promise to or agree to again in the future.
For the next time we talk about the A, I've asked him to get down to the hard stuff: describe and be accountable for the lies to me and the sneaking around.
To tell you the truth, I can't believe that my uncommunicative "Silent Sam" has actually been opening up. I can't believe how much energy and attention he's putting into trying to make things work out after years of avoidance and wishy-washy non-commitment.
This stuff is HARD, excruciating even! The cost of not doing the work would be splitting up and feeling the loss and regret. The carrot on the end of the stick to motivate us to keep going is the hope for a better relationship.
I don't know if any of this has answered your questions or helped in anyway. Good luck to you!