When news broke of Ozzy and Michelle's four year relationship back in May, Kelly, 31, shared a series of angry posts on Twitter, in which she released details of Michelle's phone number and accused her of "elder abuse".
Michelle Pugh has filed a lawsuit against Kelly Osbourne
In court documents filed this week, Michelle claimed that Kelly "intentionally and maliciously harmed her by publishing private facts and defamatory statements, in addition to inciting a rash of mass cyber-bullying against (Michelle) utilising the highly-popular social media platform Twitter, wherein Kelly had approximately 4.07 million followers".
According to the filing, Kelly did delete the phone number tweet a month after posting it, but by then the "damage was already done".
Michelle is seeking compensatory damages, attorney's fees, punitive damages, and "other relief", as the court sees fit.
Ozzy and Sharon recently confirmed their marriage is back on track
Ozzy, 67, and his wife Sharon, 63, recently announced that their 33 year marriage is "back on track" following the scandal. But this week, Michelle opened up to People about her four-year romance with Ozzy, and said he made her "feel like the most beautiful and worshipped woman in the world". She also described the Black Sabbath rocker as "the greatest love of my life".
Ozzy's rep responded to the interview with a statement, saying that the star was "sorry if Ms Pugh took their sexual relationship out of context".
Ozzy and Sharon with daughter Kelly and son Jack
It read: "He would like to apologise to the other woman he has been having sexual relationships with. Out of the bad comes good. Since his relationship with Ms Pugh was exposed, Ozzy has gone into intense therapy.
"Ozzy is mortified at what his behaviour has done to his family. He thanks God that his incredible wife Sharon is at his side to support him."