Regardless of the type of affair your man is having, the first thing you have to do when your man cheats online is put up your boundaries. You have to know what you will and won't tolerate. You should be prepared to stop being emotionally and physically intimate with him until he stops the affair. If you aren't prepared to kick him out, separtate or breakup, at least speak up and tell him that you are no longer going to be intimate with him until he stops the affair.