All depends are you close to the wife, do you want to be friends with her, or give her your phone number for her lawyer in the divorce. But If it is someone you don't really know, I would probably hit you and my husband. If you are going to say it, make sure he is right there with you, that would be the proper thing to do. But think what type of person you might be dealing with before you walk up and say sorry I was sleeping with your husband, she may turn on you and not be pretty nice about it.