The current English-only educational climate in California presents children with polarizing discourses about national belonging (Bailey 2007). This study uses language socialization theory (e.g., Garret and Baquedano-López 2002) and Bakhtin’s (1981) concept of “heteroglossia” to examine how members of a peer group of linguistic minority children attending a bilingual Spanish-English preschool in California used bilingual practices among themselves to respond to such polarizing discourses and organize their local peer group social order. The peer group was followed over several months during free play in their preschool classroom using methods of ethnography and talk-in-interaction. An extended episode of birthday play was examined. The children use code-switching as a resource to negotiate locally shifting “frames” (Goffman 1974) and participation frameworks (C. Goodwin 2007; M.H. Goodwin 1990a; 2006) during their play interaction. Through their language practices, group members reflexively portray the tension between their languages (Bakhtin 1981), and inscribe some domain associations (Garrett 2005; Paugh 2005; Schiefflin 2003) for English and Spanish (e.g., using English for references to aspects of birthday parties relevant to U.S. consumer culture; Spanish for topics of food and family). These practices reproduce hierarchical and gendered rankings of the languages inscribed in monolingual discourses of the dominant U.S. society. However, the children also challenge regimented patterns, through using, at moments, unmarked forms of code-switching, often within single utterances. These hybrid utterances blur boundaries across frames and groups of players, affirming “linguistic and cultural hybridity” (Haney 2003: 164) within the peer group.