Thanks for the great advice. I do know that she is communicating with him. On a rare occasion I was able to see some of their text messages. The interesting thing was that there was nothing sexual in the ones that I was able to read.
I did ask her once about the OM and the texting and that is when she mentioned that he is just a friend, but that he was interested in her sexually. She said that she made it pretty clear to him that to her position was that they were just friends but that he had a different approach. I also read a letter that he had written to her describing how my wife had shared very deep and personal information with him but there was no reference to any PA.
I agree with your position, that I find this whole thing very disrespectful and that having secrets is inappropriate. I would like to stay and continue to work on things, but not if she is going to keep him in and me out of her emotional contacts.
I would like to send a message to her that as long as she is living in our house she needs to respect what it means to be married and not be getting emotionally involved with other men.
Any thoughts on contacting the OM? Not sure if this would be a good strategy or not. He is married and indicated in his letter to my wife that he was unhappy with his marriage.