Attention on customer citizenship behavior (CCB) has increased markedly in recent years for both researchers and practitioners. However, existing research lacks deep understanding of the antecedents of CCB in social commerce, especially from the perspective of seller-consumer interaction relationships. Drawing on complexity theory, this study investigated the impacts of the causal configurations of three types of seller-consumer interaction relationships (experience of parasocial interaction (PSI), social interaction, and parasocial relationship (PSR)) on CCB in social commerce. To test this proposition, this study adopted fuzzy-set qualitative comparative analysis (fsQCA) on a sample of 380 experienced social commerce consumers. Our findings indicate that the combination of social interaction and PSR leads to a high CCB among social commerce consumers. Moreover, borrowing from social exchange theory, we further employed partial least squares structural equation modeling (PLS-SEM) to reanalyze the research data. The PLS-SEM results are consistent with the fsQCA results.