"Sexual Practices and Risk of HIV Infection.""No-risk activities include -- no sex, masturbation, sex only with an unifected, monogamous partner who does not share needles and syringes.""Risky activities include contact with your partern's blood, semen, or vaginal fluid, unless you know for sure that your partner does not have HIV. Some examples are -- oral, anal and vaginal sex; oran-anal contact; mutual masturbation; shared sex toys.""Scientists believe that it is unlikely that open-mouth kissing can transmit HIV."