Although previous research has found that workplace friendship has beneficial effects on employees' and organisations' consequences, knowledge regarding the complexity and dark sides of workplace friendship is limited. Our purpose is to develop and test a three-way interaction model that explains when and how negative outcomes of workplace friendship are likely to unfold considering both individual personality and contextual conditions. Based on the stressor-emotion model, we argue that workplace friendship may also be a stressor due to its conflicting and contradictory dual roles, which in turn triggers negative employees' emotions, thus, leading to withdrawal behaviour. Furthermore, we propose that emotional reactivity and task interdependence are individual and contextual factors that induce and catalyse the negative effect of workplace friendship. By analysing the data from 429 respondents, the result supported our hypotheses. Overall, our research provides a theoretical and empirical foundation for future research on the dark sides of workplace friendship.