walk away. through time the cheater will realise he made the biggest mistake of his life when you have left him. he doesnt realise how bad the situation is because he is in the picture. i know its hard, but turn a blind eye and walk away. he will realise he has lost you and if he really truly loved you he would do anything and everything to get you back.after you take him back, he wont have second thoughts of cheating, as he knows how hard it was the first time to get you back. yes, once a cheater always a cheater and "if they,ve done it before, they can do it again" runs through your mind. Hence if you see the cheater,s sincerity and love for you sometimes the saying doesnt define them. it was sincerely a one off mistake, and through that they learnt never to do it again. goodluck and follow your heart, not by reading these forums.