Of course not! If an alcoholic can quit drinking, a drug addict can stop using, or a smoker can stop smoking then it stands to reason a cheater can quit cheating! People who use the mantra; “Once a cheater always a cheater” do so in order to (protect themselves). It makes it easier to not take a chance again when you set up hard fast rules. It does not matter if the rules are based in fact or not. Each of us is entitled to live our lives the way we want to.