Sources tell ET that Ozzy had an affair with hairstylist Michelle Pugh, a colorist at the Meche Salon in Beverly Hills, California, where Sharon, as well as her daughters, Kelly and Aimee Osbourne, get their hair done.
Pugh, whose Instagram account was made private when the cheating rumors started to fly, does Ozzy's hair, a source says, but never in the salon.
"Michelle never brought up Ozzy to me, but it was known in the salon they were a little too close," a source in the salon tells ET. "Michelle is super into rock/metal music, so they bonded over that. Still, it's weird. He's nearly 70 and a client. She knows better that to do this."
The 45-year-old stylist, whose online bio says she is "inspired by rock and roll as much as she is by nature," is the former assistant of celebrity hairdresser Tracey Cunningham, and has done work for several celebrities, including Jennifer Lopez, Camila Alves, Sarah Paulson and Molly Sims.
Additionally, her work has been featured on HBO's Girls, Freeform's Pretty Little Liars, as well as booking campaigns for Gucci and styling people for Oscars red carpets.
A source close to the Osbournes told ET over the weekend that Ozzy, 67, and Sharon, 63, would be ending their marriage after more than 33 years. In the wake of the divorce news and the cheating allegations, Sharon was absent on Monday's The Talk, which was addressed on the show by co-host Julie Chen.
“Now before we get started, as you can see, Sharon is not here today. There were many tabloid headlines this past weekend about her and Ozzy, rumors and speculation that they have split up after nearly 34 years of marriage," Chen said. "Sharon understandably took today off. We are sending all of our love to her and to her family and we ask that you do the same."
Watch the video below for more on the split.