This thesis examines the heterosexual experiences of middle-class girls growing up in England between 1950 and 1980. Drawing primarily upon oral histories and Mass Observation testimonies, it explores the ways in which sexual discourses and practices shaped the adolescences lives of the post-war generation. Putting Laura Doan’s notion of ‘queerness-as-method’ into practice, the thesis uses the example of the youth sexual practice in the mid-twentieth century to reinforce claims that heterosexuality is unstable and dynamic. Paying particular attention to the logistics of sexual practice, the thesis makes two central arguments regarding youth sexuality at this time. Firstly, it argues that young women’s sexual lives were shaped by girls’ place in the life-cycle. Girls’ status as dependents and their lack of private space materially affected when and where they could engage in sexual activity. More than this, however, girls understood their adolescence as a period in which they were supposed to transition towards sexual maturity. Young women thus organised their sexual practice around the notion that they were ‘becoming sexual’. Secondly, this research demonstrates that teenage sexuality in the post-war period had an important social component. Far from being a product of individual morality, preference or personality and conducted in secret, girlhood sexuality was fundamentally social: girls’ sexual activities both defined and gained meaning from their relationships with their sexual partners, schoolmates and friends. Focussing on the politics of space, the thesis demonstrates how sexual activity was managed around competing imperatives of display and evasion as teenagers wished to hide their sexual behaviour from their parents but benefit from the social currency increasingly associated with sexual knowledge and experience. The thesis thus demonstrates the importance of understanding sexuality as being embedded within the social tapestry of individuals’ lives. For girls growing up between 1950 and 1980, questions of sex and sexuality could not be divorced from their roles and identities as not-yet-adults, girlfriends, daughters and friends.