Giuliana Rancic isn't Kelly Osbourne's only nemesis.
In her new memoir, Made In Reality, former Hills star Stephanie Pratt dishes about her bad blood with the former Fashion Police hostess, 30, RadarOnline.com can exclusively reveal.
Moments after the MTV reality series wrapped in 2010, Pratt's then-boyfriend, motocross racer Josh Hansen, dumped her without warning.
Pratt, 29, says her seemingly good pal Osbourne consoled her.
"I'm so sorry. Josh is the worst, such a dickhead," Pratt claims Osbourne assured her soon after the split. "Just keep hanging out with us, you can do so much better, forget about him."
But just one week later, Pratt says she made a shocking discovery on Perez Hilton's website.
"I see an article about Kelly Osbourne and Josh Hansen on a date!" she writes. "Part of me was glad to have made up my mind that this guy was good for nothing, but most of me just felt heartbroken."
The next year, Pratt crossed paths with her former friend once again when the two both auditioned for a presenting role on Fashion Police.
"It was down to the final two for that role, me and Kelly Osbourne," Pratt says. "And, as you know, it went to Kelly…I wanted to be furious about that, especially after what had happened between us over Josh. But I decided not to think about Kelly much after that."
"I will never admit to liking Giuliana because I don't," she recently said. "I don't think she's a good person and I think she's a liar."
Are you Team Stephanie or Team Kelly? Sound off in the comments.