Mr. Flibble,
You asked about polygraph advice. I have been thinking of your post for days. My WH's affair story is similar to your WF. We are about 4.5 to 5 years out now.
I asked for a polygraph very soon after finding out. I wasn't sure of why I wanted it or how much credibility I gave to the process, but I thought a passed polygraph would ease my mind. My WH took care of every part of choosing the company, scheduling, and attending on his own. I didn't want to spend my time on it. It all happened within a month of D-day.
I was asked for 3 or 4 questions that were yes or no. I choose to focus only on physical events and wanted to word them so they were technically sound. I don't remember the exact wording, but the intent was:
Have you told me the entire extent of this affair physically?
Have you had any contact with the AP that I'm not aware of since the discovery?
Have you have any sexual interaction with anyone else since we've been married ?(engaged/dated? I don't remember what I thought was important.)
The polygraph company gave feedback on the questions and wording via email before the test. There has been no "parking lot confession" or even changing any substantial details of the affair since the first few days.
After the polygraph, I was given a written report. It had numbers and confidence levels and a written interpretation. The numbers said my WH technically passed 2 of 3 questions and failed for the one of other sexual interaction. In the polygrapher's written interpretation, he said he felt the entire test was inconclusive. He also said that it was his professional opinion that my WH was trying to evade the test, and he didn't believe his story. Similar to your WW, my WH had one physical contact event where he claims he stopped at about the same level of interaction. That's even less believable on SI because he's a man, right?
I didn't really know what to do with that report. It left me feeling that a polygraph is much more interpretational than scientific. I was not ready to leave my marriage over that test and report. I did not feel confident in polygraphs in general.
We continued to try in our marriage with several ICs for us both, MC, even a separation. About 1- 1.5 yr later, we decided to do another polygraph. At this point I was ready to fully leave the marriage if it was false. It was more that I was searching for some peace and some answer than my confidence in polygraphs.
My WH still had the same basic story of his affair since the first few days of discovery. However, he did tell me many painful things about his state of mind and things that were said that I would have no way of finding out otherwise. In terms of other past sexual interactions, there was pushing boundaries in my view and flirting with other women. The most significant was probably a woman jumping on his back for a group picture, and he grabbed her butt.
We jointly chose the polygraph company and person. I felt comfortable with their experience. The questions/intent were the same. The polygrapher spoke to us jointly at first in the exam room. He said he had a policy of confirming results with his partner before releasing a conclusion. I left to a waiting room area while the exam was conducted. At one point, my WH came out of the exam and told me he was having the same feelings as before with the same question. The hair was standing up on the back of his neck, and he had a tingling sensation. WH said there was nothing else he could remember, but he also thought he would fail the test.
It was a long drive home. We both assumed my WH failed, and he understood it was the end for me. WH knew I was planning to move out but offered to leave immediately to a hotel and do whatever was helpful to me for divorce. The polygraph administrator called and said he was confident that my WH passed. The time delay was the review/verification with his partner.
I don't know what to think of polygraphs. In hindsight, I think they are maybe more interpretational than I am comfortable with using as a decision-making devise. Yet, I'm also fairly confident that I now have my WH's full personal truth of events. But that is only as a complete story 4-5 years out from the affair and with new knowledge of my WH and how he thinks and acts. An affair is a wake-up that you don't really know your spouse and your marriage.
Mr. F, I don't know if this helps you or not. I'm really sorry with your situation and what you are going through. I can tell my full story later if it will help you.