Gender inequality in housework has been the center of sociological research for decades and continues to be a topic of public interest. Despite extensive sociological attention, many questions about gendered housework over the life course and across diverse family and household forms have received limited attention in the mainstream literature. This dissertation focuses on housework and gender in three specific family-household contexts to offer insight into questions about the stability and ambiguity of gender relations: repartnering, family complexity, and shared households. Amidst increasing cohabitation rates and union instability, heterosexual women and men are likely to form and dissolve multiple marital and non-marital unions with different partners over the life course. However, sociologists know very little how past relationships affect current ones, particularly whether people change their housework arrangements upon repartnering and whether women and men experience similar patterns of change. Drawing on life course and gender theories and prospective longitudinal data, the first paper tests competing hypotheses about the effect of repartnering on individuals' levels and shares of housework. I find that women and men perform the same amount and share of housework in their second union as they did in their first union. However, there is also evidence that women's share of housework slightly declines in their second union. The results suggest that although the life course is dynamic, gender roles are stable amid union instability. The second paper focuses on family complexity. Past research highlighted the Incomplete Institution hypothesis to explain the more egalitarian division of housework in remarriages and stepfamilies. The explanation suggests that family complexity introduces ambiguity to family life, resulting in a more egalitarian division of labor. In this paper, I investigate the gender dynamics in complex families by examining men's relative housework shares across different family structures from 1985 to 2017. I find that although in the earlier period (1985-1989), men in stepfamilies had greater shares of housework than men in two-biological parent families and blended families, stepfathers' housework behavior has converged over time. In contrast, men in stepmother families have consistently shared housework more equally than other men. Additional decomposition analysis suggests that between half and 61% of the gap between men in stepmother families and men in other family structures are attributed to selection. The findings challenge the Incomplete Institution hypothesis and highlight how parental roles cement the gendered division of housework in heterosexual unions. As most housework research, the first two papers exclusively focus on families and couples. However, demographic and economic trends have changed people's living arrangements and delayed family formation. In the third paper, I offer an alternative setting for studying "doing gender" through housework - shared living households where young adults live together but do not share romantic or kinship relationships (i.e., roommates). I find that women and men "do gender" via housework in shared households and that young men are particularly resistant to cleaning, regardless of their roommates' gender. Moreover, the results show that women living with men spent more time cleaning than men living with women. In contrast, women and men, regardless of their household's gender composition, spent a similar amount of time on other “female-typed” tasks, “male-typed,” and gender-neutral tasks. The findings underscore that housework carries a gendered meaning beyond the context of families and how cleaning is a core site for men's masculinity. Taken together, the dissertation demonstrate the overall stability and similarity of men’s low housework participation across contexts.