Living with HIV is a particular situation in which external constraints such as treatment, secrecy around HIV status, and systematic use of condom on one side, and representations combining HIV and sexuality on a specific way, on the other side, are mixed. We studied the subjective experience of sexuality among HIV positive young adults, , investigating the impact of gender and mode of contamination on representations of sexuality, assuming them as a subjective adjustment between the subjective world and the life story of an individual, within the socio-cultural context where they are living. 21 semi structured interviews concerning young adults of the two genders contaminated by mother to child transmission and by sexual transmission, aged 18 to 25 years and living in France, were collected. They were analysed using a method based on Grounded theory. Inside the research group, depending on the contamination mode and the gender of the subject, we noticed different life experiences with the HIV virus leading to different sexuality experiences. For those subjects that were infected by sexual intercourse, we noticed three types of experience. For subjects infected by mother to child transmission, the experience of sexuality was quite similar. We showed how secrecy around seropositivity or its disclosure to the sexual partner are organizing sexual activity (sexual abstinence, casual relationships, long term/lasting relationships) and sexual experience. We also analysed how the systematic use of the condom could became a sign of the disease likely to lead to unprotected sexual relations. For all subjects, we observed how representation combining HIV with transgressive sexuality is crucial within their experience of sexuality.