A high-quality parent–child relationship is critical to the health and well-being of adolescents and, in the family system, the interaction pattern within couples is a decisive factor in parent–adolescent relationship quality. Using dyadic data from 441 Chinese couples, in this study, we examined the association between partner phubbing (a negative interaction behavior initiated by the spouse) and parent–adolescent relationship quality, and further explored the moderating effect of adolescent gender. Dyadic modeling showed that partner phubbing had both an intra-person effect and an inter-person effect on parent–adolescent relationship quality. For the intra-person effect, husbands’ phubbing had an adverse effect on the mother–adolescent relationship quality, and this effect was stronger for girls than boys; wives’ phubbing had a positive effect on the father–adolescent relationship quality, but this effect was only significant for boys. For the inter-person effect, the negative influence of husbands’ phubbing on father–adolescent relationship quality was only significant for boys; wives’ phubbing was uncorrelated with mother–adolescent relationship quality. These findings deepen our understanding of the links between the marital subsystem and the parent-adolescent subsystem in the family, underscore the importance of positive marital interactions for adolescent development, and have implications for personal smartphone use management in family contexts.