This study documents the notion of unilateral translanguaging--the configuration of translanguaging spaces to disproportionately privilege a dominant language or its speakers. We analyze four teachers' translanguaging practices in a Portuguese-English two-way immersion (TWI) program in the United States. Rather than focusing on whether and how translanguaging occurs, we highlight temporality and purpose to explore when and why participants engaged in translingual practices. Data stem from a three-year ethnographic project and include semi-structured interviews and classroom observations. We found that translanguaging mainly occurred during Portuguese lessons, during which teachers used English to give directions, discipline students, and give important announcements, linking English use to moments of high authority. English-dominant students' translanguaging practices also tended to be more readily accepted than those of Portuguese-dominant students. Furthermore, in contrast to prior research on language status as unconscious bias, our findings demonstrate teachers' keen awareness of practices and policies that disproportionately benefit English-dominant students. Still, structural conditions, parental power dynamics, and pressure to maintain the program left the focal teachers feeling unequipped to interrupt these practices. This research highlights how educators' practices and perceptions of translanguaging interact with structural features of bilingual education programming as factors that may disrupt or reproduce inequities.