I vaguely remember reading that repeated exposures to HIV can delay seroconversion, not sure where. Take this situation... A man has unproteced sex with an HIV positive individual, a few weeks later he has unprotected sex with a new partner who is a virgin and obviously uninfected and may have infected her, he continues to have unprotected sex with this girl and gets tested 3 months after the possible exposure with the first partner. Obviously he could have only got infected from the first partner, but if he had infected the second partner could the repeated exposures with her delay his seroconversion?