Controversial Katie gave her thoughts on Kelly's Oscars gown on Sunday, sharing a photo of a Troll figurine alongside the caption: "Nice of Kelly O to make such an effort for Oscar night."
Well, never one to back down, an angry Kelly has now replied.
Kelly tweeted: "The perfect role 4 U would be Mr. Cellophane in "Chicago", as your jealousy is that transparent. Aren't u bored of being mean?"
She followed this with another tweet: "That's right - #CBB is over & no 1 gives a f**k about U anymore. What a sad old woman U R that it takes me to make U relevant."
Katie responded: "Bird, you are supposed to be at the Oscars. Focus, love, focus. Love, like Jesus and Lily Allen – it took your dad to make you relevant twinkle xxx Get working that carpet."
Kelly, who is the daughter of Ozzy and Sharon Osbourne, was at the Oscars to comment on the red carpet fashion as part of E!'s Fashion Police team.
Katie, meanwhile, commented via Twitter.
The controversial columnist appeared in the last series of CBB, where she finished runner-up to Katie Price in the grand finale.
More red carpet Oscars fashion:
Copyright: Rex Features Jim Smeal/BEI
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