This study investigates two concurrent trends across Europe and North America: the increasing instability of parental unions and men’s rising contributions to household work. Because children have almost universally resided with their mothers and it is difficult for non-residential fathers to maintain any levels of care work, union dissolutions have potentially slowed societal increases in gender equality. A new family form—50/50 living arrangements—has begun to challenge our understanding of the consequences of union dissolution. Since 50/50 residence requires fathers to take full care responsibility for the child half of the time—something few partnered fathers do—it may even push parents into a more egalitarian division of care work. We have studied care work using Swedish administrative data on parents’ leave from work to care for a sick child. We have created a panel of leave-sharing for children aged 2–11, and use an event-study design to estimate the causal effect of dissolution on the sharing of sick-child leave. The results show that in parental unions dissolving today, the dissolution leads to an increase in fathers’ share of sick-child leave. Whereas union dissolutions have for decades been slowing the gender revolution in Sweden, they are now accelerating it.