Love Question

If somebody ask u this question what will u say: he has been married for so long and all while the wife has been suspecting that he was having affair outside their matrimonial home, only to find out that her husband is one of the best in the world. Unfortunately, her husband doesn't love her any more yet they are living together and the wife want things to be as it used to be when they started. The Man's question is this "what can he do to start loving her wife again? (is this possible or not) if u have the answer please send.

Thanks
Mr Ben