Might Valentine's Day, despite its marketing as a holiday to enhance romantic relationships, paradoxically facilitate their demise? Because Valentine's Day provides a useful opportunity for exploring the potential influences of recurring culture-wide events on relationships, we asked college students in romantic relationships about relationship stability, quality, beliefs, and processes, both 1 week prior to and 1 week after Valentine's Day. As predicted, those participating during the time period straddling Valentine's Day were more likely to break up than were those participating in comparison time periods. This increase in relationship dissolution appeared attributable to the catalyzing effect that Valentine's Day had on moderately strong and weak relationships already on a downward trajectory: These relationships were particularly likely to dissolve during the Valentine's Day period. We view this research as a useful illustration of how to conceptualize and empirically investigate the effects of holidays and other cultural events on relationship dynamics and outcomes.