If Wife then starts dating platonic male friend shortly thereafter (or becoming even more serious than dating, such as becoming engaged), that could be used to show that there may have been the opportunity and inclination to have an extra-marital affair.
Dating and intimate relationships create some questions for people who are separated but not yet legally divorced. From a legal standpoint, there are two things you need to consider. North Carolina requires that spouses live “separate and apart from each other” with at least one of them intending to end (terminate in legalese) the marriage. You have to live in a separate residence — not in separate rooms of the family house, not even in a separate apartment over the family garage — but in an entirely separate location.
Qualifying for Separation in NC Each state’s separation laws work differently and North Carolina is no exception.
That’s it:  separate residence and  intention to end the marriage.
You do not have to file a legal document to begin a separation, although some people prefer to do so.
Let’s consider the following issues to help you determine what may be the best choice for you.
If there is a suspicion you may have had an extra-marital affair, it may be wise to delay dating until your case is settled or you are officially divorced.