This article reports a longitudinal case study of two German high‐school exchange students’ 5.5‐month study abroad (SA) in New Zealand, examining their social lives and oral second language (L2) development. Six informal interviews, weekly diary entries, and monthly summaries were used to elicit data about their overseas experiences and reflections associated with them. The qualitative analysis investigated the nature of the students’ social lives at school, in their homestay, in their hobbies, and during their free time. The results demonstrated that opportunities for L2 engagement varied considerably with context—some affording and others restricting interaction. Especially the presence of co‐nationals impeded L2 interaction and required the students to seek out opportunities themselves—an effort that the students were not always willing to make. For the quantitative analysis, the interview data were coded using multiple measures of complexity, accuracy, lexis, and fluency (CALF). Compared to previous studies, the results showed that all CALF dimensions improved during SA, but just for one student and not in a linear fashion. The two learners’ L2 profiles varied considerably, demonstrating that development is dynamic and unique and that interpretations of it need to take account of the learners’ social contexts and what they make of these.