This article examines the liminal space that exists both as a structural condition engendered by transnational migration and as a state that is self-consciously carved out by migrants. It demonstrates that this space provides the grounds for migrants to develop deviant heterosexuality', such as extramarital relationships while simultaneously causing dilemmas and contestation of gender dynamics in conjugal and familial relationships. Drawing on ethnographic research and in-depth interviews, I elucidate the extramarital relationships among migrant Filipino workers in South Korea. By incorporating discussions of queer heterosexualities' and Hubbard's geographical engagement of sexuality into analysis, I argue that migrants' extramarital practices are shaped not only by dominant discourse, but also through the particular social and spatial positioning of individuals. First, I demonstrate that the liminal space gives migrant Filipino workers a certain degree of autonomy from the power and ideological interventions of both sending and host societies. Second, I highlight the liminal space that is extended by migrants themselves, especially through the increasing economic ability and mobility of migrant women, which can reconfigure the modes of heteronormativity and gender structure in conjugal, familial and extramarital relationships. In the end, I argue that transnational migration results not only in provisional liminality but also prolonged liminality through migrants' initiative in pursuing their desired heterosexuality and their endeavour to convert extramarital relationships into long-term intimacy. This study contributes to the discussion of the interplay between heterosexuality/heteronormativity and gender in recent human migration.