Young people's exposure to social network sites such as Facebook is increasing, along with the potential for such use to complicate romantic relationships. Yet, little is known about the overlaps between the online and offline worlds. We extended previous research by investigating the links between Facebook intrusion, jealousy in romantic relationships, and relationship outcomes in a sample of undergraduates currently in a romantic relationship. A Facebook Intrusion Questionnaire was developed based on key features of technological (behavioral) addictions. An eight-item Facebook Intrusion Questionnaire with a single-factor structure was supported; internal consistency was high. Facebook intrusion was linked to relationship dissatisfaction, via jealous cognitions and surveillance behaviors. The results highlight the possibility of high levels of Facebook intrusion spilling over into romantic relationships, resulting in problems such as jealousy and dissatisfaction. The results have implications for romantic relationships and for Facebook users in general.