Integrating insights from cultural sociology and identity theory, I explore the mental health consequences of adolescent romantic relationship inauthenticity—incongruence between thoughts/feelings and actions within romantic contexts. Applying sequence analysis to National Longitudinal Study of Adolescent Health data, I measure relationship inauthenticity by quantifying the extent to which the ordering of events of actual romantic relationships (e.g., holding hands, saying “I love you”) diverges from the sequence of events within idealized relationship scripts among 5,316 adolescents. I then test its association with severe depression, suicide ideation, and suicide attempt. I find that romantic relationship inauthenticity is positively associated with the risk of all three markers of poor mental health, but only for girls. This study highlights the importance of gender and culture in determining how early romantic involvement influences psychological well-being.