Talk with parents and extended family about sex and relationships can support adolescents’ sexual health. However, few studies explore how parent and extended family communication with adolescents intersect. This study used thematic analysis to assess family roles in talk with teens about sex and relationships among a sample of 39 adult extended family members (such as aunts and uncles, and older siblings and cousins) in the United States. Analyses identified four themes in sexuality communication that address: why adolescents talk to extended family about sex and relationships, family engagement in these conversations, consistency of family messages, and family communication about adolescents. Findings identify variation in how family members interact with adolescents and one another regarding talk about sex and relationships. For example, some participants described family coordination of sexual messages to the teen, while others reported no family communication about this topic. Results also showed similarities and differences in how sibling and non-sibling extended family describe these processes. These findings identify the need to examine family talk about sex and relationships in the context of a larger family system, rather than only within dyadic relationships, and suggests possibilities for family-based interventions to support adolescents’ sexual health.