This paper aims to understand why and how young Muslim women pursue sexual relationships in the urban bustees (slums) of Kolkata, West Bengal, India. I discuss how girls in heterosexual romantic relationships decide where, when and how to have sex, and the importance of class discourses and popular Bollywood culture in this decision-making process. Premarital sex is haram, or a forbidden act in Islam, and I will describe how girls in this research negotiate their Muslim identity whilst pursuing sexual relations with their boyfriends. Sex before marriage is also socially unacceptable in the bustee, and throughout this paper I show why young women negotiate various social risks to pursue sexual relationships. I demonstrate that girls are not overtly challenging the normative discourses of sex, gender arrangements and religious expectations in public spaces. Rather, they manipulate the norms of the "good Muslim girl" in public in order to maintain sexual relationships with their boyfriends in private. (Contains 1 figure and 9 notes.)