Sustainability working groups play a crucial role in fostering sustainability-driven innovations. However, these groups often face tensions that hinder members from developing the essential emotional and affective commitment needed for effective collaboration. Moreover, our understanding of the group dynamics underlying tension-laden affective commitment remains limited. To address this gap, we investigate how tension resolution manifests as resonance-seeking behavior in the micro-practices of a working group. Our findings reveal that group members engage in mimicry within micro-practices to navigate tensions, following specific patterns that shape their prospective sensemaking.