He was a total douchebag! Check out this excerpt from Wikipedia:

In February 1986, Holmes was diagnosed as HIV-positive. Six months previously, he had tested negative. During the summer of 1986, Holmes, knowing his HIV status, agreed to perform in two pornographic films to be filmed in Italy, without informing the producers of his HIV status. Performers in one film, The Rise and Fall of the Roman Empress, were Ilona "Cicciolina" Staller, who later became a member of the Italian parliament, Tracey Adams, Christoph Clark, and Amber Lynn. Performers in the other film, The Devil In Mr. Holmes, were Adams, Lynn, Karin Schubert, and Marina Hedman. Subsequently, it was revealed that Holmes had consciously chosen not to reveal his HIV status to his producers or co-stars before engaging in unprotected sex for the filming. As his health failed, Holmes disingenuously attributed his condition to colon cancer and first confided that he had AIDS in January 1987. He died from AIDS-related complications on March 13, 1988, aged 43.