In this article, we examine personal narratives on premarital sex by two generations of Polish men and women—one born in the 1950s and 1960s, and their parents’ generation, born in the 1920s and 1930s and coming of age during or after World War II—and place these in dialogue with discourses surrounding young sexuality in state-socialist Poland. Using sociological surveys, popular sexological literature, and Catholic marriage preparation material, we contextualize accounts of premarital heterosexual experiences, provided through oral history interviews and contest memoirs—ego documents submitted for autobiographic writing competitions in the 1960s and 1970s. We show there was no clear division between public secular and Catholic approaches to premarital (hetero)sexuality, with both opposing sexual experimentation before and beyond marriage throughout the state-socialist period (1945–1989). However, across the same period, young people’s acceptance of premarital sexual experimentation increased and the importance of a woman remaining a virgin until marriage declined. Our analysis of discourses and experiences reveals the connections and intersections of secular and Catholic realms. While secular experts did not conceptualize premarital sex as a sin, they often mirrored Catholic views by framing their discourse in terms of love, sex, responsibility, and potential risk. Young people negotiated various elements of these teachings in their premarital sexual practices, which, during the final decades of state socialism, were largely normalized, especially when couples were planning to marry.