WH,
This is developing exactly as I would expect it to, all of this just steers harder into exactly what I previously said to you and I take no joy in saying that. I know full well how much this hurts, how difficult it is to accept and I truly feel for you. I promise, I do.
As soon as I said something she got defensive and it started an argument she says that if I need to believe what I need to believe to move on then so be it. Problem is that I don’t want to believe something I want her to tell me what it was so that I can feel like she is being honest with me. She says things about herself like I’m a horrible person and I don’t want to be with her anymore all things I’ve never said. I get so upset it’s like she is putting words in my mouth.
Getting defensive and casting blame onto you are more classic signs of infidelity. I went through all of this. She is currently showing no signs of true remorse. Nor is she even willing to be honest with you about what truly happened. Things are being drastically minimized to try to protect herself. Shes in no way thinking of you, or the harm she has caused you.
It also seems that she is used to you caving when she gets upset. She makes you question yourself, instead of her. These are typical deflection techniques.
What you need to keep in mind:
Im not saying your marriage was perfect or that you have done everything right. None of us have. But her decision to engage with another person while married to you was hers and hers alone. If she truly had concerns with you and your marriage, she should of spoken with you or started the divorce process. It doesnt in any way excuse Adultery.
Stick with the polygraph. My gut says she's going to do anything she can to get out of it once the date approaches. That could look like blaming you and starting a huge fight, refusing to do it for any number of reasons, faking an emergency, you name it. It could look like an assortment of things. But the key to it is, she doesnt go.
As far as questions, you do need to keep it yes or no and 3 to 4.
My suggestions:
While married to WH, Have you ever had sex with anyone other than your husband WH?
While married to WH, have you ever sent nude photos to anyone other than your husband WH?
While married to WH, did you ever have sex with (APs Name)?
While married to WH, did you ever send nude photos to (APs Name)?
Purpose:
These will cover whether she cheated with him or anyone else.
Keep in Mind:
Even if she does go and take the test, (which i doubt based on everything you've said), she will still minimize this after.
They only admit to what they have to. So once caught with a polygraph, expect her response to be, it was only one time. But keep in mind, her previous story was it never happened. Nor is her one time story true. Trickle truth is very common in this scenerio.
The question for you will be, is knowing she cheated enough to make the decisions you need about your life? Or will you need to know how many times, how long it went on for, etc.
If so you could always schedule another polygraph down the line, but it will need to be phrased in yes or no questions.
Again, im truly sorry to hear your going through this WH, it was definitely the worst experience of my life, so I feel for you.
Good luck and stay strong!