Unearned preferential treatment has been shown to negatively affect bystander customers who observe the treatment but do not receive the benefit. In two studies we examine the watchers’ unfairness perception under different relationship norms. Study 1 compares unearned preferential treatment granted by a hotel versus a host of peer-to-peer accommodation. The unfairness perception is higher in the latter case. The sense of community in the peer-to-peer platform imbues consumers’ evaluation of their interactions with their peer-to-peer hosts with a different perspective based on communal norms. To directly test its moderating role, relationship norm is manipulated in Study 2, which shows that a communal relationship sensitizes the bystander to the unfair treatment that is considered a violation of the communal norms. This unfairness perception is found to have implications for satisfaction and repurchase intention.