This study aims to explain consumers’ impulse buying behavior in Da Nang City through second-screen usage within the context of social commerce. Based on the Stimulus-Organism-Response (S-O-R) framework, the research proposes a model to examine the role of parasocial interaction in stimulating impulse buying behavior. The findings reveal that when consumers are deeply immersed in the storyline they are watching, their motivation to use social media increases, along with their tendency to engage in social comparison with celebrities, forming parasocial interactions, stimulating consumers’s impulse buying behavior. Additionally, the credibility and attractiveness of celebrities further encourage consumers to develop parasocial relationships, thereby strengthening their impulse buying tendencies. Data were collected through a survey of consumers in Da Nang and analyzed using Structural Equation Modeling (SEM) to test the proposed hypotheses. The results provide additional empirical evidence on the role of parasocial relationships in a multi-screen social commerce environment and offer managerial implications for businesses in designing marketing strategies that integrate entertainment content with shopping activities.