system
guilty: I cheated on my girlfriend once.
human
I cheated on my girl friend once and haven't told her. 
human
Oh boy, that is a very delicate situation. Do you plan on telling her?
human
I feel guilty but I know I will lose her if I tell her.
human
I understand your fear, but it will be worse of you keep that big of a secret from her, especially if she finds out some other way.