Second language (L2) researchers have long acknowledged that affective variables (e.g., anxiety, motivation, positive emotions) are essential in understanding L2 learner psychology and behavior, both of which influence communication and have implications for language learning. However, there is little research investigating affective variables during L2 interaction, particularly from a dynamic rather than a static, trait-oriented perspective. Therefore, this study examined 60 L2 English speakers’ affective responses in real time during a paired discussion task using galvanic skin response sensors to capture speakers’ anxiety. Analyses focused on speakers’ speech, their behavioral reactions, and the content of their discussion while experiencing anxiety episodes (high vs. low arousals). Findings revealed that speakers glanced away, blinked, and used self-adaption gestures (touching face, hair-twisting) significantly more frequently during high arousals than low arousals, whereas head nods were found to occur significantly more often during low arousals. In comparison to low arousals, a larger proportion of high arousals occurred while discussing personal topics. Implications are discussed in terms of the role of affective variables in communication processes.