Adultery during separation?

Adultery is a crime in North Carolina; however it has not been prosecuted in the last century. Adultery is the act of engaging in sexual relations outside of a marriage, and can be done openly or in secret. If you decided to pursue an action you have two options in the civil arena Alienation of Affection and Criminal Conversation.

For an Alienation claim you will need to prove that you and your wife had a happy marriage, and that but for her paramour

I have discovered some facts about my wife during our separation.
First, the man she is with now is a lawyer (I believe). They met in March of 2008. In May or June she lunched with him and sought advise about our marriage. Then in July she asked for a separation.
In october I moved out, and two days later she was photographed in public on a date with the same man.
They have since begun a sexual relationship, which he has demanded remain a secret. Mind you, I caught them outside of a hotel in November, so he is aware that I know it is him and what is going on.
I believe that he became her friend and gave her advice that clearly led to him coming into the picture within days of my moving out.
However, the event in which their date occurred two days after I had moved out was a private event that required a guest list, and thus required him to be on that list well in advance, signalling to me that plans were made before I moved out.

She and I have not signed a separation agreement though we split time with our son (who she essentially took with her when she moved out). I agreed to allow her space and time and let her take our son because it was indicated that we could find a way to begin working on things in that space and time.

However, if this man had been pursuing her for many months (as it is believed by more than just me) and he gave her advise about our marriage, then began to seriously pursue her and was seen with her only two days after I was gone, I have to believe that one reason he is adamant to keep their “affair” such a secret now is because he knows the law enough to know that I can make a strong case for alientation of affection on his part.

But what is the standard on one party having sex with someone else during a separation that is not legally signed? How is adultery viewed in NC in this manner?

Because she is sleeping with him in secret, does it constitute adultery even though we are living apart now?

And is there grounds for alienation of affection suit against him?

Thanks.