The rapid expansion of the sharing economy has ignited diverse perspectives regarding its sustainability implications. Nevertheless, a comprehensive study examining the influence of host–guest interactions on sustainable consumption behaviour is yet to be conducted. To fill the abovementioned gap, this research crawls online data and corresponding consumer reviews of 46,360 properties listed on Muniao Short Rent. Employing latent Dirichlet allocation (LDA) to model sustainable consumption reviews and conducting subsequent regression analysis using SPSS, this research empirically demonstrates that the host–guest interaction frequencies and positive emotions during interaction positively influence guests’ sustainable consumption behaviours within the sharing-accommodation context. This research proposes the significance of the host–guest relationship for green consumers and argues that factors such as price and house type negatively moderate the host–guest interactions and guests’ sustainable consumption initiatives.