Patterns of extradyadic involvement (EDI) were assessed for three samples: an undergraduate dating sample and a community marital sample reporting on an actual experience of EDI, and an undergraduate sample which denied recent EDI and was asked to imagine a hypothetical experience of EDI. Good consistency of responses within and between measures was found for the hypothetical EDI sample. Persons reporting on a hypothetical EDI were generally less approving of EDI and imagined that they would experience higher levels of primary relationship satisfaction, overall remorse, and specific types of distress, particularly in comparison to the dating EDI group. Relative to the dating EDI group, the marital EDI group recalled greater dissonance with the EDI behavior, more concern about disapproval from others, and higher levels of intimacy, self-esteem, and love reasons for the EDI. No differences were found among the groups on the level of emotional closeness with the extradyadic partner.