During his years of drug and alcohol abuse, the Black Sabbath frontman cheated on his manager spouse with a succession of women, until in 1986, Sharon put her foot down and insisted he undergo testing for the sexually-transmitted disease.
Sharon says, "(He admitted sleeping with) some old tart he picked up at a bar. I wanted to give him a shock. And it certainly did that.
"Ozzy was terrified of Aids. The test required a blood sample and the doctor said we would get the result back in a week.
"We went to get the result together. Positive - so I knew I would have to be tested too. Ozzy was mortified.
"I said to the doctor, 'Take some blood from me, then take three more vials from Ozzy and send them to three different labs and with three different names on.
"I knew from my gay friends that in those days the test was so unsophisticated and delicate that it only had to be shaken and you could get the wrong result.
"All the results came back negative. That was the last time he was unfaithful, ever."
The now-faithful Ozzy and Sharon renewed their wedding vows at a star-studded New Year's Eve ceremony in December 2002 (31DEC02).