Although collaborative consumption platforms (CCPs) have achieved rapid growth, the increase in misbehavior on CCPs has made users hesitant to participate. This study examines how previous moral behavior influences subsequent moral behavior and how deindividuation and self-disclosure, as psychological mechanisms, influence subsequent moral behavior. To test the hypotheses, this study conducted two experiments. Data were analyzed using logistic regression analysis. The results show that the previous user’s misbehavior (or good behavior) positively affects the subsequent user’s misbehavior (or good behavior). Furthermore, without self-disclosure, deindividuation mediates the effect of the previous user’s misbehavior on the subsequent user’s misbehavior. Conversely, when there is self-disclosure, self-presentation mediates the effect of the previous user’s good behavior on the subsequent user’s good behavior. The study provides a diffusion model of moral behavior on CCPs through a dual mechanism of deindividuation and self-presentation while considering self-disclosure as a nudge.