This study examined the interaction effects between Hong Kong adolescents’ exposure to sexually explicit online materials (SEOM) and individual, family, peer, and cultural factors on their beliefs about gender role equality and body-centered sexuality. Based on a survey design with a sample of 503 high school students in Hong Kong, the results indicated that adolescents’ frequency of accessing SEOM, their intrapersonal reactions to SEOM, their communication with parents about sexuality, their susceptibility to peer pressure, and their acceptance of cultural values regarding sex roles work jointly to affect their conceptions of gender and sexuality, although the main and interaction effects differ across variables. The results partially supported the hypotheses that individual responses to SEOM and relationships with parents and peers with regard to sexuality interact with SEOM exposure in affecting the outcomes. The study provided evidence for the adoption of an ecological perspective to guide the provision of sexuality education.