Most bilingual children often display greater proficiency and preference for one of their two languages. Researchers refer to this asymmetry as language dominance. However, despite being possible to determine the overall language dominance in bilinguals, there may be substantial flexibility in their language use. In particular, the relative ease of using each language may depend on the sociolinguistic context and the language of the interlocutor which may affect the ease of accessing words in a given language. In the present work, we investigate whether and how the sociolinguistic context in an International English medium school influences bilingual children's vocabulary production. Specifically, we examine whether bilingual first-grade children's expressive vocabulary skills vary as a function of the linguistic context ("Home/School") and the language ("English/Spanish") of their conversational partner. Results showed that contextual factors interacted with child's language performance. The participants' ability to name objects in Spanish was affected by the conversational partner's language, and their ability to name "Home"-context words varied by language. The findings of this investigation highlight the importance of considering sociolinguistic factors when evaluating bilingual children's language skills.