Right now, marriage and monogamy feature prominently on the public stage. Efforts to lift prohibitions on same-sex marriage in this country and abroad have inspired people on all sides of the political spectrum to speak about the virtues of monogamy’s core institution and to express views on who should be included within it. The focus of this article is different. Like an “unmannerly wedding guest,” this article invites the reader to pause amidst the whirlwind of marriage talk and to think critically about monogamy and its alternatives.