This study charted the longitudinal trajectories of wives' and husbands' reports of marital love, satisfaction, and conflict and explored whether and how first- and second-born offspring's pubertal development was related to marital changes. Data were drawn from the first 7 years of a longitudinal study of family relationships. Participants included wives, husbands, and first- and second-born children from 188 White, working- and middle-class families. Multilevel models revealed declines over time in wives' and husbands' reports of marital love and satisfaction but only small changes in conflict. Offspring's pubertal development was related to changes in marital qualities; declines in positivity and increases in negativity were most consistently linked to firstborns' puberty. Overall, the results highlight the interrelatedness of family subsystems.