Yes, your wife has to ask God for forgiveness and as winter said maybe the guy did not know she was married. My ex use to cheat on me all the time and it had nothing to do with our marriage as it was shortly after we were married, but that of his own lust. I forgave him, but the trust was broken and never gained again as he continued in this act with other women and I eventually left him as even though he kept asking for forgiveness it never stopped.