At what point? Perhaps when we start moralizing on how others should live their life. Something about being a self-righteous leader seems to be a good step towards embarrasing yourself in public.
Also, I agree with Ohio about the braodh brush. I'm a non-cheating male - not because I'm morally superior to anyone, but because I don't want to hurt my spouse.
At what point? Perhaps more seriously, at the point where we care equally about the needs of others as well as our own desires.