This study examined the longitudinal relationship between work–family conflict (WFC) and family–work conflict (FWC), with a focus on the moderating role of job demands and home demands, and the mediating role of family distress within dyads (i.e., actor [the employee] and partner). Using data from a survey of 281 married partners (N = 562) from Central Java, Indonesia, in two waves, four months apart, this study’s results revealed that WFC has a spillover effect on FWC in the cross-sectional path, but not longitudinally. Furthermore, family distress actor was found to mediate the relationship between WFC and FWC in the cross-sectional spillover path, whereas family distress partner did not, indicating that family distress underscores the detrimental impact of WFC on family functioning. Additionally, only cognitive job demands were found to moderate the relationships between WFC and family distress actor, WFC and family distress partner, and family distress actor and FWC over time.