It's hard when husbands and wives don't stick to their vows, some men make a decision to cheat on their wives. Even when it's a brief affair, while in cases it lasts for many years. The first thing you may have do is ensure that you're correct and that you are not just imagining that he's committing adultery.You need to keep an eye on your husband, his whereabouts, phone calls he receives, and possibly email activity because if this woman is indeed a crazy woman he wouldn't keep contacting her, watch for any change in his work schedule. If your husband never worked any overtime and suddenly says he has to stay late, see if there's a pattern to it. If it occurs only on certain days of the week, this may be when he's meeting her. If you have access to his pay information, make certain there is overtime on them.
Sometimes when a man is married he often isn't as concerned with how he dresses or keeping in shape. When he meets a woman who is interested in him, he may try to change for her. If your husband suddenly goes on a diet, buys new clothes or has his hair different, chances are that he may not be making changes for you or for himself, but for the women he is interested in. Just be mindful of any changes your husband makes to improve his appearance. One thing you could do is confront him, if you accuse him, he may accuse you of being paranoid. He can be so convincing that you will feel guilt for thinking he was being unfaithful. If you feel guilty about wondering where your marriage is headed, DON'T! He will think that if you feel guilty you will never question him again because he made her feel so bad. If he isn't doing anything wrong, there's no reason for him to become overly defensive.
For your families sake seeking marriage counseling may be your best options and a last resort if you find out that he has been cheating while he was away from you or even now for your son's sake and if you have to leave you will leave knowing you have tried everything and can also find closure if leaving is your decision as to what to do. It's very disrespectful for your husband to cross any boundaries as far as women friends are concerned and until he learns self respect, respect of his mate and self control he will always have this issue.