This article examines moral hypocrisy and the self-serving bias (SSB) in the sexual infidelity context. We found evidence of self-serving attributions that occur between primary relationship partners following sexual betrayals. Specifically, we found that sexual infidelity perpetrators (a) blamed their primary dyadic partners (i.e., victims) for infidelities significantly more than those victims blamed themselves for such infidelities, (b) blamed the surrounding circumstances for infidelities significantly more than their victims did, and (c) rated the emotional impact of infidelities on their victims as significantly less than victims' ratings of such impact. Moreover, we found that participants with prior experience as both sexual infidelity perpetrators and victims displayed "sexual hypocrisy" by judging others more harshly than themselves for sexually unfaithful behavior. Our findings demonstrate that personality variables associated with sexual infidelity (narcissism, sexual narcissism, avoidant attachment, and primary psychopathy) are also relevant to self-serving attributions in the sexual infidelity context.