This ethnographic study conducted among young women aged 18-21 years in Chiang Mai, northern Thailand, explored the parental control mechanisms imposed by Thai middle-class families on the sexuality of their daughters. It addressed the ways in which young women tactically use the social media in order to negotiate the sexual controls they encountered in everyday life. Taking the teenage girls' point of view, this paper argues that, as active agents, young women achieve a certain level of sexual autonomy and construct their own sexual selves in modern northern Thai society, despite their parents' attempts to prevent this. The paper highlights the ways in which social media are used by Thai girls in order to achieve such a goal. Research findings should inform the development of future programmes on sexual health promotion, parental skills and sexual communication between Thai parents and their children.