On social network sites (SNS), information about one's romantic partner is readily available and public for friends. The paper focuses on the negative (SNS jealousy) and positive (SNS relationship happiness) consequences of SNS use for romantic relationships. We examined whether relationship satisfaction, trait jealousy, SNS use and need for popularity predicted these emotional consequences of SNS use and tested the moderating role of self-esteem. For low self-esteem individuals, need for popularity predicted jealousy and relationship happiness. For high-self-esteem individuals, SNS use for grooming was the main predictor. Low-self-esteem individuals try to compensate their low self-esteem by creating an idealized picture. Undesirable information threatens this picture, and especially individuals with a high need for popularity react with SNS jealousy. © 2011 International Communication Association.