Oral sex is a common and normative part of young people's sexual behavior, yet there is concern that young people perceive oral sex as a casual, non-intimate behavior. The current study used a qualitative methodology to improve our understanding of the factors that contributed to university students' perceptions of the intimacy of sexual behaviors. Participants included 50 women and 35 men (17-24 years old) who responded to an open-ended intimacy questionnaire which asked them to describe the reasons for their perception of the relative intimacy of oral sex and intercourse. Responses were analyzed using conventional content analysis procedures. The majority (91 %) of participants perceived intercourse as more intimate than oral sex. Five key themes emerged from participant responses. Participants perceived intercourse as more intimate than oral sex because: (1) it is a symbol of love and commitment; (2) it is mutual; (3) it involves greater risks and benefits; and (4) oral sex is not discussed. A small subset perceived oral sex as more intimate than intercourse because (5) it required focusing on a partner. Overall, the findings highlight the role of formal and informal education in shaping young people's perceptions of the intimacy of sexual behavior.