" In monogamy, a romantic partner and a sexual partner are, almost by definition, the same person. Emotional intimacy and physical intimacy are so tightly entwined that some self-help books speak of "emotional infidelity" and encourage married couples not to permit each other to become too close to their friends. Advice columnists and television personalities will speak gravely of the dangers that "emotional affairs" pose to a monogamous marriage and ask, "Is emotional infidelity worse than sexual infidelity?" Monogamy can leave surprisingly little room for close friendships, much less nonsexual romances. "

― Franklin Veaux , More Than Two: A Practical Guide to Ethical Polyamory