The feminist critique of public/private or political/domestic spheres must make sense of a twist in HBO’s Big Love. Nineteenth century conceptualizations of the family and the separate spheres ideology, predicated on heteromonogamy, cannot account for the experiences of some groups participating in “new kinship” patterns. For example, when Mormon polygamists leave culturally polygamous communities for the city and attempt to integrate into the dominant paradigm of U.S. heterosexual marriage, they may experience patterns of patriarchy unlike those of other new kinship-based groups/social movements. Passing for monogamous is a burden for Margene, a third wife in a family of four Mormon adults who “live the principle,” by participating in plural marriage in suburban Utah. The family lives in a “compound” that appears to be 3 distinct family units from the street, but whose yard allows the family of 11 to travel between family subunits easily. Lonely for adult companionship, Margene invites a friendly neighbor over to watch a video. Ben, the eldest son—the biological son of the first wife, observes the neighbor’s departure from around the corner of the front of his home, which is located 2 houses down from Margene’s, and maps new relationship boundaries when he confronts Margene. In this plural family, Margene (21) and Ben (15) are the closest in age between the adult and child generations. They often behave as though they are siblings or friends, rather than parent and child. When Ben confronts Margene about her inappropriate social behavior, he illustrates how separate spheres critiques must take into account the specificity of and uniqueness of new kinship situations. In effect, Margene’s domestic sphere is differently constrained, despite certain transhistorical and superficial similarities with 19th century marital relations, by both her relative lack of authority over her own household and her relationship with her son. As third wife, Margene is at the bottom of the marital hierarchy, and as mother to an adolescent boy, her authority takes second place to Ben’s when Ben is left in charge of the family in his father’s absence. Such a representation of the separate spheres ideology and its consequences invites questions about the cultural construction of kinship and how critiques of social contract theory have excluded some participants in new kinship systems from the transformation of private and public politics.