A qualitative approach was used to explore the meaning and perceptions of cheating in adolescent romantic relationships. Mexican American and White adolescents (N = 75; 53.3% girls; 56.1% Mexican American), separated by gender and ethnicity into 12 focus groups (three groups per type), discussed personal and peer experiences of cheating in dating relationships as both the victim and perpetrator. Dialogue was coded using inductive content analysis; two broader cheating themes encompassing six sub-themes emerged 1) perceptions of cheating (individual-oriented, peer-oriented, and frequency of occurrence) and 2) consequences of cheating (commitment, emotional responses, and relationship outcomes). Mexican American girls spoke most frequently and strongly about cheating, followed by White girls. The meaning and contexts of cheating by ethnicity and gender has important implications for promoting healthy dating behavior during adolescence. (Contains 2 tables.)