Research on infidelity-related distress has focused on victims with little attention to perpetrators. Two studies therefore explore the psychological functioning of individuals who have engaged in dating infidelity. Study 1 showed that, compared to faithful partners, individuals who had engaged in infidelity showed more psychological distress. Study 2 investigated the interrelationships among infidelity, psychological distress, and relationship satisfaction over time. Results suggested that initial levels of psychological distress predicted later infidelity but infidelity did not predict subsequent psychological distress. Findings are interpreted in light of the broader infidelity literature, potential mechanisms are suggested, and avenues for future research are recommended.