Drawing on gender structure and life course theories, this article examines how heterosexual couples “undo gender” in their work–family arrangements within the conservative context of Switzerland. Focusing on how gendered norms and expectations are challenged, we explore in a longitudinal analysis the influence of both partners’ gender ideologies on paid and unpaid work arrangements across family life stages. Using couple data from the Swiss Household Panel (2002–2020), we estimate pooled and fixed-effects linear probability models to analyze both between-couple and within-couple determinants in undoing gender. We find diversity in how gender is undone in paid and unpaid work arrangements across couples’ gender ideologies and family life stages: While gender ideologies consistently influence paid work arrangements, they affect unpaid work arrangements only for couples living with children. Strong egalitarian ideologies can overcome gendered norms and unsupportive institutions, especially when both partners share these beliefs. However, these ideologies only partially mitigate macro-level constraints. Still, a significant minority of couples challenge dominant norms, particularly in their paid work arrangements. Our findings highlight the need for policy reform to establish supportive institutions that empower couples to align their behaviors with their gender ideologies, paving the way for greater equality in the future.