Kelly Osbourne Goes Off on Christina Aguilera, Calls Her a 'Fat B%^ch' and a 'C&nt'

Note to self: do not anger Kelly Osbourne. Apparently that chick holds a grudge...

Osbourne showed up on E!'s "Fashion Police" with Joan Rivers at a recent taping, and the talk turned to Christina Aguilera. Rivers talked about how she "looked like Snooki's Scandinavian cousin" at a recent German fashion event, and that was all it took to light Osbourne's very short fuse.

"Maybe she is just becoming the fat b**ch she was born to be. I don't know," said Osbourne. Woah.

The two have been feuding for years, since Aguilera bought the Osbourne's 11,571-square-foot, 6-bedroom, 10-bathroom house for $12 million.

As USA Today reports, "At the MTV Europe Music Awards in November 2003, the network aired a skit of Aguilera throwing darts at a photo of Osbourne. When she took the stage, she mocked Ozzy's daughter as well, saying: 'Oh Lord, I didn't realize it was still Halloween.'"

Sounds like that was all fuel enough for the feisty Osbourne.

"She was a c*** to me. And she bought my house!" she said.

Osbourne went on: "She called me fat for so many f***ing years, so you know what? F*** you! You're fat too."

Was Osbourne simply exacting karmic revenge for years of fat jokes now that she's trimmed down, or is she still a little screwed up over the loss of her close friend Amy Winehouse?

Either way, it's clear that Kelly's got more than a little bit of her bathead-eating father Ozzy's f%^&-it-all genes.