Often the core reason for this is seeking out an experience that might boost one's personal self esteem. Going out without any signs of ties and seeing if someone will pursue him and tell him how attractive he is and in some way desirable. This is about his own ego and not something he will be able to adequately explain to you so he will most likely want to avoid discussing it and act like it's nothing. Some men have a hard time when their wife's attention isn't all about them anymore and she is paying attention to their children and is busier. This is a clue he is attention seeking.

How old is your husband and how long have you been married?