Many people engage in intrusive behaviors in close relationships. Existing research links intrusive behaviors to a lack of trust and an imbalance between self- and partner-interest. The authors tested the novel hypothesis that people need self-control to regulate intrusive behaviors. Self-control enables people to forgo their self-interests (reassurance or closeness) for the sake of their partner or the relationship. Specifically, we predicted that people need both trust and self-control to refrain from intrusive behavior. One-hundred-eighty-nine couples participated in a prospective longitudinal study with three waves. Consistent with predictions, multilevel analyses revealed an interaction between trust and self-control on intrusive behaviors cross-sectionally as well as longitudinally (albeit marginally). These results provide support for our hypothesis that neither trust in the partner nor self-control is sufficient to forestall intrusive behaviors, but rather both are necessary to refrain from intruding into one's partner's privacy. © 2013 American Psychological Association.