“Be an enigma. Don’t show them your vulnerability. Don’t try to plead or reason with them, or tell them you care. That’s power to a cheater. I know you don’t see it that way, but you’re not empathy- and character-deficient the way they are. This person has just demonstrated to you in the most intimate and humiliating way how little respect they have for your feelings. So it stands to reason that they cannot be trusted with more of your feelings.”