While overnight work-travel (OWT) declined significantly in 2020, it has steadily rebounded and remains a common job demand. Yet despite its continued relevance, few studies have examined how features of OWT – such as its duration – are associated with travelers’ well-being. Using data from a cross-sectional sample of employed heterosexual U.S. respondents (N = 183) in dual-earning, married or cohabiting relationships who travel for work, this study examines (1) whether the association between OWT duration and psychological distress is moderated by a family-based demand: the traveler’s perception of their partner’s work interfering with the partner’s family life (partner work-to-family conflict), and (2) whether this moderated association is explained by heightened spousal conflict and family-to-work conflict. Multivariate results indicate that longer OWT is associated with higher distress only among those perceiving high partner work-to-family conflict. Moreover, this association is explained by higher spousal conflict and family-to-work conflict. As OWT becomes more common in a post-pandemic world, these findings underscore the importance of relational dynamics in shaping mental health outcomes for employees who travel for work, and call for replication in more diverse populations and across diverse family and couple structures.