Feminist movements and advancements in women’s careers suggest that strides have been made towards gender equality. However, power dynamics in heterosexual relationships remain unbalanced. Seemingly innocuous traditions around proposals, weddings, and surname changes are symbolic of wider gender inequality. Widely endorsed traditions surrounding marriage proposals and surname changes may seem innocent and inconsequential but have been associated with higher levels of benevolent sexism (BS) in university students in the USA. The studies in this thesis examined participants’ perceptions of these traditions as well of individuals who break traditions. Studies 1-3 (Chapter 2) extended research to adolescents (dating age) and 30-year-olds (typical first-time marriage age). For the first time, these studies additionally examined gendered wedding traditions (e.g., a father walking a bride down the aisle). Different combinations of ambivalent sexism predicted participants’ opinions about surname change after marriage and the choice of children’s surnames. In younger adolescents (11–18 years; n = 144), hostile sexism (HS) predicted endorsement of surname change, whereas benevolent sexism predicted endorsement in 16- to 18-year-olds (n = 142) and 30-year-olds (n = 81). In adolescent samples, both BS and HS predicted endorsement of patronymic traditions for children, whereas only BS did in the adult sample. The findings suggest that different types of sexism are linked to traditional beliefs in specific age groups. This thesis also examined perceptions of surname traditions because studies suggest that women who break surname traditions (retaining their surnames) are considered less committed, loving partners and their male partners are ineffectual. Studies 4a (16-18 years; n = 188) and 4b (19-22 years; n = 201) extended this research by exploring adolescents’ perceptions of men and women breaking surname traditions as well as by including an understudied circumstance: men adopting women’s surnames in the design. In contrast to previous studies, young people did not judge men and women more harshly for breaking surname traditions. Instead, they showed a preference for a man changing his name and identified this as a feminist choice. Study 5 (18-25 years; n = 241) expanded on the literature by exploring whether participants judged a woman differently based on whether the surname decision was justified based on an agentic (professional identity) or communal (family identity) reason. Surname decision and reasoning did not interact to influence perceptions. However, participants favoured a woman who prioritised her professional identity and rated her as more compatible with her partner than a woman who prioritised maintaining her family identity. They also gave higher favourability to her male partner when the woman prioritised her professional identity over maintaining her family identity. The thesis concludes that younger generations may be adopting more liberal views on marriage traditions and surname decisions, particularly women and girls. My findings extend the link between ambivalent sexism and endorsement of heterosexist traditions that appear innocuous and suggest that choices made in romantic relationships could have serious consequences for wider gender equality. As a result, multiple levels of intervention may be required to reduce sexism and promote equality in society.