Social networking Web sites, such as Facebook, have changed the way in which people communicate online. The present study examined the relationship between jealousy and Facebook use experimentally by asking participants to imagine viewing their romantic partner's Facebook page. We varied the hypothetical privacy settings and number of photos of the couple publicly available on Facebook. Results indicated that imagined privacy settings and the presence of couple photos affected negative emotions (jealousy, anger, disgust, and hurt). Furthermore, we found sex differences indicating that women felt more intense negative emotions after thinking about the fictitious scenario than did men, particularly when evidence of infidelity was public to others. These results have implications for sex differences in jealousy and suggest that the manner in which people employ Facebook privacy settings can be negative for romantic relationships.