Q: Can I get HIV from someone performing oral sex on me?

A: Yes, it is possible for you to become infected with HIV through receiving oral sex, but it is considered low to medium risk, though no one knows exactly what the degree of risk is. Evidence suggests that the risk is less than that of unprotected anal or vaginal sex. If your partner has HIV, blood from his or her mouth may enter the urethra (the piss-slit, or opening at the tip of the cock), the vagina, the anus or ass-hole, or directly into the body through small cuts or open sores.
If you choose to have oral sex, and your partner is male:

use a latex condom on the cock; or
if you or your partner is allergic to latex, use a plastic (polyurethane) condom.
If you aren't going to use a condom, you can reduce your risk of HIV infection by avoiding deep-throating (also known as "face fucking" or "throat fucking"). Deep-throating makes it easier for the piss-slit of your cock to come into contact with the mucous membranes at the back of your partner's throat, providing a good entry point for HIV to get into the body's blood stream.
If you choose to have oral sex, and your partner is female:

use a latex barrier (such as a dental dam or a cut-open condom that makes a square) between your mouth and the vagina. Plastic food wrap also can be used as a barrier. Using a barrier will reduce the risk of blood or vaginal fluids entering your mouth.
Research has shown the effectiveness of latex condoms used on the cock for preventing the transmission of HIV. Condoms are not risk-free, but they greatly reduce your risk of becoming HIV-infected if your partner has the virus.