I'm really going to go out on a limb here and risk getting shot down in flames but it feels like I am reading my own story and I finally got somewhere with my fwh who was hiding facts from me.
I tried everything to get him to tell the truth. He admitted to 95% of it but for some reason decided I didn't need to know everything. The stuff he held back just showed how he really was a willing participant, even pursuer, in the A. I guess that's why he held it back. He liked to blame her.
Anyway, there were some thing that he kept from me. I knew there was more in my gut but I couldn't get him to open up. He kept swearing I knew it all. It drove me virtually insane. It was cruel and unnecessary. I couldn't understand.
Then I put myself in his shoes.
I am NOT blaming myself here, and I am NOT suggesting you react how I did. I just want to share what's working for us.
I realised how it must feel to be him. Facing the agony on your partner's face knowing you caused that pain. The fear that if you spill the beans you could very well lose them. I never reacted well. I would freak out at every revelation so I took a step back.
First I offered him an amnesty, I knew he was lying about a village cash withdrawal so I gave him a 24 hour amnesty to tell me anything and everything. I did freak out while I was waiting but I did that mostly on here and when he told me i had decided to stay as calm as i could so he would open up. He confessed to meeting her two other times at her second job in a pub. He was a mess when he told me. He said he was so scared his lies were going to cost him his marriage and the longer it went on the harder it was to tell me.
So then I had a think. I realised I wasn't going to stick to my vow that any more lies would make me leave. Instead I told him that I loved him so much almost nothing he could say would make me leave. I had seen enough changes in him over the past year to know he was still the man for me and that I could see our bright future now he was being honest.
I knew there was a chance there was more so I told him, look I know you had sex, what else is there that could make me leave? if you cheated before, I would cope, if you had sex more than once, I would cope. I have seen how this A has changed you and the man you're becoming. I want to be with that man but only if you're completely honest. There really is no point in lying, you're not protecting anyone.
I then said if he remembered anything else to come to me. I asked him to write a timeline. He had started one reluctantly ages ago but never finished it. This time he was keen. He has been working on it every day in his lunch hour at work. It's not just a timeline though. He has responded really well and written a full account. His feelings, justifications, the works. He is getting it all out now.
A couple more minor things have come up as writing the account has jogged his memory. I am confident now that I have the truth, finally.... my gut is quiet and a strange but great thing is happening. I am feeling more secure, the affair is moving into the background naturally in my head, we are getting closer.
So, if you really want to stay no matter what maybe try telling her she is safe to share anything with you, that you understand how hard it is to be honest after lying for so long.
Really different to the usual advice but maybe worth a go.
Take this with a huge pinch of salt if it sounds all wrong to you, just cos it was right for us doesn't mean it will be for you but I thought I would take a big risk on going against the grain and share it with you.
Also, on the poly, I decided against it cos I need to be able to trust him in time cos I can't do a poly every time I doubt him. Also cos say for example I asked, have you told me the whole truth about the affair? And he failed, he would confess to some minor thing and then I would want to re test to check again. we don't have that sort of money so I went with the 'save environment to confess' plan.
I am so nervous writing this cos I know it's a bit of an out there idea and will only really be of any use if you would stay virtually no matter what and possibly if you also get very upset by revelations. I don't know.
Just my thoughts
ETA - it helps that this is the only thing he has ever really lied about. He was a really honest guy before cheating. So I am fairly confident the affair made him a liar and he's not a liar by nature.
Also since the confessions and writing his account a strange thing has happened. I feel lots better and ready to move forward BUT he is more emotional, easily crying and being quite clingy. I think it's made him face what he really did and not the version he told me. I think in the long run this will be good for us.