This article studies a specific form of transnational living that results from Thai–Western cross‐border marriage migration: Thai women's experiences of intercultural partnerships with a Western man. The study is explicitly from a Thai female partner's perspective. It unpacks women's experiences and perceptions of living this life from their own accounts. We refer to their experiences and perceptions of living this form of transnational life as unintended transnationalism, that is, that living a life defined by dependent gendered intercultural exchanges with a foreign man was a by‐product, not an aspiration of her strategy for a better life. Living ‘unintended transnationalism’ refers to how women negotiate the specific high challenges and sociocultural pressures arising from dependency on a foreign man, who largely decides where, when and how you live. Women face strong acculturation pressures to adapt to their husbands' Western cultural needs, on his terms, even when they share a home in Thailand—a process we define as imported assimilationism. The study shows how her experiences of transnational living are importantly shaped by her: access to rights, cultural differences with her partner, and positioning in social space and place in Thailand, over this life journey. It draws from 20 biographical interviews with women in partnerships (between 7 and 30 years) with Westerners, currently resident in Thailand. Overall, we find that living ‘unintended transnationalism’ is a challenging life, even for women who make significant material gains. It can lead to isolation, dissociation from family, and dissimilation from belonging in Thailand.