A growing body of work exploring transnational interaction has brought to light the importance of awareness of multilingualism in research contexts, yet little consideration has been given to researchers working in a later learned language (LX) or the process of investigating linguistically diverse communities. This research takes place within a multilingual social space, a transnational Spanish language group in London, against the backdrop of a globalized and mobile world. The work explores the complexities of conducting research in a multilingual, international, and transient context where sharing all language varieties and/or cultures with participants may not be practical, possible, or even preferable. The data, collected by myself (a participant-researcher), includes recordings of informal social conversations, ethnographic observations, and interviews with key participants. Their analysis highlights linguistic adaptation to facilitate transnational understanding, demonstrates the value of interviews in a common LX, and considers how language ideologies and norms affect transcription of multiple language varieties. The paper argues that utilizing an ethnographic lens, particularly when working in an LX, allows for a deeper understanding of localized multilingual interaction through closeness to the participants and advocates a slow, detailed approach to data analysis.