When a guy hits the point of ejaculation during sex or oral activities, what happens if his own semen gets into a cut on his body. Can a guy's own semen infect him? If so is there any particular place on his body that would be vulnerable to infection if he had a cut or opening to the bloodstream? Also, does a person have to already be infected to spread HIV?
You cannot get infected with HIV by coming into contact with your own fluids, nor if you have sex with a person who is not infected with HIV. The virus is never "created" by sexual activity, drug use, masturbation, or medication. Also, if the virus were present in your semen, you would already be infected.
HIV, like some other viruses and bacteria, is transmitted from one person to another when an UNINFECTED person's mucous membranes (lining of the rectum, vagina, urethra, or mouth) or bloodstream comes into contact with HIV infected fluid (blood, semen, vaginal secretions, breast milk). HIV is primarily transmitted through vaginal and anal intercourse without condoms, blood-to-blood contact (injection needles), and mother-to-infant, with an INFECTED person.
Solo-masturbation poses no risk for disease transmission. It is probably the safest sexual activity you can engage in. And, in the words of Woody Allen (I'm paraphrasing), it's sex with someone that you love.