I keep thinking when I read your updates that both of you want to make this work but just don't know how to do it. Like the scene you describe of her looking for shoes I wonder if your W was hoping you would comment on how attractive she looked and how maybe more would happen. Not that this would fix things.
Don't want to give you false hope but something doesn't add up. Some will say she is just cake eating. But I am not sure.
As to your son. Kids are smart. They will figure it out one day. He might ask you in five or six years if there was someone else or how you must have felt and he will appreciate that you didn't try to trash his mom. That requires strength but you don't want to go down the path where both his parents start using their child to basically trash the other person. Like I said, this is incredibly hard and you want to scream it from the roof tops. Believe me...I wanted to scream it to everyone how much my W betrayed me...everyone thinks she is such a nice and wonderful person.
Truth is my W was embarrassed the affair occurred and was definitely ashamed after I discovered details. (some will say she is only ashamed about the latter but I doubt that). She needed to let go of her shame and focus on guilt. It may very well be that your W needs the same. So what you see as deception (which it really is) might in her situation be very much an internal conflict. Also, women often get seen as being flirting with men when they are just trying to be nice. I wasn't there so maybe it was actual flirting. But from my female students I hear all the time how men that they just want to be friends with think the woman is flirting with them just by her smiling at him.
Some will disagree with this advice but I wonder what she will say if you told her she looked amazing and when she was on all fours you got all sorts of ideas.
I really also wonder what would happen if both of you go to counseling. I know you want some things to change first but maybe those things will change after you go together.
