Research demonstrating that employees who are undermined at work engage in similar behavior at home suggests this connection reflects displaced aggression. In contrast, the present study draws on self-regulation theory to examine the work-home undermining spillover/crossover process. We propose that poor sleep quality transmits the influence of workplace undermining to home undermining per self-regulatory impairment, and exercise moderates this indirect effect per self-regulatory improvement. Using matched data from 118 employees and a member of their household to test our model, results demonstrated that undermining experienced from supervisors increased subjective (i.e., self-reported) but not objective (i.e., actigraph-recorded) sleep difficulties, which, in turn, increased the frequency with which individuals engaged in undermining at home (as reported by cohabitants). Additionally, indirect effects occurred for employees with low but not high levels of physical exercise (as measured by self-reports, step counts, and energy expenditure). Our findings suggest sleep and exercise may serve as valuable intervention points to prevent the spread of harmful behavior across contexts. Implications for theory and practice are discussed.