Over a long enough time line, the vast majority of us will experience a lapse in discipline that will cause us to fail to live up to our standards for ourselves. While this is already sufficiently aversive, we typically make matters worse by denying ourselves the pleasure inherent in the lapse -- which is often the only consolation of the problematic behavior. So if you're going to cheat, indulge. At least allow yourself to enjoy the fleeting experience. And if you can't bring yourself to do so, perhaps you will be more motivated to stay disciplined.