© 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.Very few studies have investigated the relationship between sensory processing sensitivity (SPS) and interpersonal variables; none has particularly focused on romantic relationship satisfaction. In the context of romantic relationships, this study aimed to identify whether SPS is a risk factor (hypothesizing that traits make individuals more vulnerable to the effects of adverse environments) or a susceptibility marker (hypothesizing that traits make individuals more susceptible to the effects of both nourishing and adverse environments). To understand this, we tested whether an increased level of SPS is associated with a decreased level of romantic relationship satisfaction through negative affectivity and conflict resolution styles. Furthermore, we tested whether these proposed relationships intensified when the childhood environment was negative. A total of 206 unmarried young adults who had been in a romantic relationship for at least two years completed the measures of SPS, childhood environment, negative affectivity, conflict resolution styles, and relationship satisfaction. The results indicated that negative affectivity and negative conflict resolution styles mediated the association between SPS and satisfaction in a relationship; however, childhood environment did not moderate these relationships. These findings suggest that beyond childhood factors, SPS is an independent risk factor for developing negative outcomes in romantic relationships. This study also significantly contributes to the literature by revealing the possible mechanisms between SPS and romantic relationship satisfaction.