This study is a 3-year follow-up of 746 adolescents on the evolution of perceived conflicting or instrumental relationships between sport, education, and friendship. School-to-sport conflict increases with age, in particular among boys, and is maximal among adolescents self-determined toward sport but not toward school. Sport-to-school instrumentality increases among boys, decreases among girls, and is positively linked to contextual self-determined motivation. Friendship-to-sport conflict is more prevalent at the beginning and the end of adolescence, among girls, and is negatively linked to friendship self-determined motivation. Sport-to-friendship instrumentality decreases during adolescence, in particular for females, and is positively associated with contextual self-determined motivation.