Because of the potential stepparent-stepchild relationships have for tension and conflict, clinicians have identified the development of a positive stepparent-stepchild connection as one of the major tasks of stepfamily life. Stepparents often are advised to focus initially on developing friendships with stepchildren, or seeking affinity with them, particularly early in the life of the relationship. Both family systems theory and evolutionary theory suggest that stepparents’ affinity-seeking behaviors are related to the quality and functioning of other stepfamily dyads, such as couple relationships, and the whole stepfamily. We extend prior work on stepparents’ affinity seeking by including perceptions of both members of the stepcouple about affinity seeking, stepfather-stepchild conflicts, couple relationship quality, and stepfamily cohesion. Stepfathers and mothers from 234 stepcouples independently completed online surveys. After accounting for covariates (i.e., duration of mothers’ previous relationships, duration of the stepcouple relationship, focal child’s biological sex and age, number of children in the household, and mothers’ report of household income), stepfathers’ perceptions of affinity-seeking with the focal child significantly predicted both partners’ perceptions of stepfather-stepchild conflict, marital quality, marital confidence, and stepfamily cohesion. Mothers’ perceptions of stepfathers’ affinity-seeking were significantly related to her marital confidence and perceptions of stepfamily cohesion. Stepfathers’ perceptions of their affinity-seeking explained more variance in stepfathers’ and mothers’ outcomes than did mothers’ perceptions. The results suggest benefits associated with stepfather affinity-seeking—less conflict with stepchildren, better couple relationships, and closer stepfamily ties. Our findings provide evidence for encouraging stepparents to focus on building affinity with stepchildren.