Three studies explored how parental infidelity is related to offspring's infidelity behavior and used social learning theory to test potential mechanisms. In Study 1, parental infidelity was positively associated with offspring infidelity; trust and relationship self-efficacy did not mediate the association. In Study 2, infidelity was associated with parental infidelity and more positive infidelity beliefs. In Study 3, parental infidelity was positively associated with offspring infidelity. Study 3 revealed that parental infidelity is associated with offspring reports of receiving negative messages about fidelity and positive messages about infidelity from their family of origin. These communications are linked to more positive and accepting infidelity beliefs. The results of these studies support the conclusion that parent infidelity is associated with an individual's own infidelity.