Kelly Osbourne had a hard pill to swallow on Sunday's Watch What Happens Live.
During Andy Cohen's "Plead the Fifth" segment, in which he asks tough questions to his first-time guests, the Bravo host addressed the E! Fashion Police critic's ongoing feud with The Voice coach Christina Aguilera.
"You and my girl Christina Aguilera have been in something of a feud -- say three nice things about Christina Aguilera," Cohen prompted.
With her demeanor calm, cool and collected, the 27-year-old star responded smoothly, "I think she's looking way better right now, she's got a great voice and she's got a beautiful son."
Back in August, Osbourne made her real feelings known about blonde singer, 31, when she had a sudden outburst on an episode of E!'s Fashion Police.
While host Joan Rivers was discussing Aguilera's appearance, Osbourne chimed in: "Maybe she is just becoming the fat bitch she was born to be. I don't know. She was a c**t to me. And she bought my house!"
Her digs at Aguilera's fluctuating weight didn't end there. "She called me fat for so many f***ing years," Osbourne continued, "so you know what? F**k you! You're fat too."
A few months later, the Brit's fiery feelings were still burning strong.
"She called me fat for years," Osbourne said when Aguilera was once again a victim of Rivers' sharp-tongued critiques. "I was never that fat."
This article originally appeared on Usmagazine.com: Kelly Osbourne Ends Christina Aguilera Feud