Understanding extradyadic sex and its underlying motives through a dualistic model of sexual passion

Extradyadic sex in monogamous romantic relationships represents a violation of trust that has been associated with adverse personal and relationship outcomes. Although relational factors related to extradyadic sex have been extensively studied, few individual sexual factors have been identified, and these factors have remained one-dimensional. The present research proposes that sexual passion, as defined by the dualistic model of sexual passion, can help better understand extradyadic sex and its underlying motives by distinguishing two types of sexual passion. Study 1 (631 students, mean age = 24.92 years) showed that obsessive sexual passion (OSP), but not harmonious sexual passion (HSP), was related to past extradyadic sex, conflict between sexuality and the maintenance of long-term romantic relationships, and ego-invested motives for engaging in extradyadic sex. Study 2 (84 students, mean age = 28.49 years) used a longitudinal design and showed that OSP, but not HSP, predicted prospective extradyadic sex. In addition, results revealed that men with an OSP reported engaging in extradyadic sex more often and with more partners than other individuals. These studies underline the importance of using a two-dimensional approach to understand how sexual passion relates to extradyadic sex.