Recent research and conventional wisdom suggest that behavioral demonstrations of trust by supervisors toward their subordinates are most effective when those demonstrations match subordinates' desires. In the present research, we offer a more nuanced view by identifying one downside of a match between supervisors’ expressions with subordinates’ desired trusting behaviors (i.e., trust congruence). Drawing on social exchange theory and social cognition theory, we argue that trust congruence helps promote positive social exchange relationships between supervisors and subordinates. The desire to maintain or reinforce these relationships, in turn, leads subordinates to engage in unethical pro-supervisor behavior indirectly via moral disengagement. We further argue that ethical leadership represents an important boundary condition with regard to this process, as it guides subordinates’ social exchange responses and thus prevents them from engaging in behaviors that are not aligned with the ethical expectations of their supervisors. Our model is supported by two time-lagged field studies. This research improves our understanding of the ethical consequences of trust congruence and has practical implications for organizations seeking to support trust-building initiatives.