Simone de Beauvoir's novel She Came to Stay follows Françoise and her partner Pierre as their intimacy becomes increasingly entangled with the young and tempestuous Xavière. Many readings of the novel explain Françoise's bad feeling and eventual violence as symptoms of sexual jealousy. The book has also been read as a veiled autobiography of Beauvoir and Sartre's similar entanglement with Olga Kosakiewicz, so that, very often, Françoise's jealousy is assumed to stand in for Beauvoir's own. This article is about misreading in two ways. First, I argue that the common view that this is a story in part or in whole about sexual jealousy reflects a radical simplification of the emotional and interpersonal dynamics of the “trio.” Second, I argue that this interpretive simplification is in fact common in mainstream readings of nonmonogamous relationships, where “jealousy” is used to name any and all bad feelings in the vicinity of the nonmonogamous relationship, and where that bad feeling is interpreted as caused by the nonmonogamy itself. To conclude, I suggest that She Came to Stay, and particularly its notorious ending, can be seen as Beauvoir's depiction—and refusal—of the misreadings that constitute the “situation” of nonmonogamy in everyday life.