When in a romantic relationship, the experience of partners' use of multiple social media platforms varies from serving as a means of gratification to being a cause of discomfort in these relationships. To examine this new and expanding phenomenon, this study employed the media multiplexity theory to explore the roles of using multiple forms of social media when in a romantic relationship. Through the face‐to‐face, in‐depth, and semistructured interviews of 25 romantic partners, the study examined romantic partners' experience of social media use and its influence on their romantic relationships. The results showed how multiplexity in social media use facilitates satisfaction, affection, jealousy, monitoring of romantic partners, infidelity, and distraction. The findings also revealed that while using social media to facilitate satisfaction in romantic relationships, if not appropriately used, the use of social media might lead to romantic dissatisfaction.