Blurred boundaries are driven by mobile communication technologies and encompass connectivity with work after the designated work hours and dealing with private issues during work hours (i.e., cyberloafing). In the literature, both directions of boundary crossings are generally researched separately with a focus on after-hour connectivity and mostly based on the assumption that it leads to work-nonwork conflict. However, self-determined work and integrating work and nonwork might evoke boundary crossings from both domains having a potentially reciprocal effect. We conducted two empirical studies to explore the relationship between after-hour connectivity and cyberloafing. In Study 1 (cross-sectional), our between-person analysis showed that after-hour connectivity and cyberloafing have an interaction effect on balance satisfaction. When both directions of boundary crossings are strong, the negative relationship between after-hour connectivity and balance satisfaction disappears. Based on a diary study, our within-person analysis showed that cyberloafing during work hours only increases workers’ after-hour connectivity, when there are unfinished work tasks. Vice versa, workers who engage in after-hour connectivity seek to make up for lost nonwork time by increasing cyberloafing when they are highly absorbed in work. In our discussion, we take a mental accounting perspective to complement boundary theory.