Connecting informal and formal language teaching and learning has gained prominence as a way to understand language development among teenagers, but questions remain regarding its application in L2 contexts. This study investigates the significance of such connections in two L2 English classes taught by the same teacher, where students were learning English during a technology-based project, the Time Traveller. We collected data during three weeks of fieldwork at a Norwegian secondary school. We found that informal and formal language teaching and learning were connected in two ways: the students' use of English outside school was primarily linked to online game play and social media, and the teacher was able to design activities that extended her students' existing affinity space, resulting in the students using English in the classroom more frequently and more confidently than before. Implications include the importance of understanding students' informal language learning to rethink L2 teaching practices.