Whereas much research addresses relations of youths' heterosexual romantic relationships with sexual and/or delinquent activities, less attention has been paid to youths' more normative, day-to-day activities with romantic partners. This gap in the literature is problematic given that these activities define the substance of the relationships and likely are connected to relationship satisfaction. In the current study, 223 youths in fifth (28 boys; 32 girls), eighth (31 boys; 40 girls), and eleventh (36 boys; 56 girls) grades reporting current romantic relationships indicated their engagement in activities with romantic partners and relationship satisfaction. Findings revealed important grade differences in activity involvement, with eighth- and eleventh-graders reporting higher engagement than fifth-graders, especially in out-of-school activities. Additionally, engagement in out-of-school activities was most strongly associated with relationship satisfaction for all grades. (Contains 3 tables.)