Kelly Osbourne slammed Lady Gaga over the weekend regarding a "happy birthday" gesture, telling the singer to "eat my s--t" and calling her a hypocrite.

The comments came after the Applause singer appeared on United Kingdom's The X Factor on Sunday, Oct. 27, and gave judge Sharon Osbourne a cake for Kelly's 29th birthday, which she celebrated that same day. However, Gaga's gesture was not appreciated by Kelly. The Fashion Police co-host took to social media to blast the singer in a series of messages.

"Not to be ungrateful but why would you send me a birthday cake via my MOTHER in a country half the would away? #JustSendItToME #LoveNotWar," she tweeted Oct. 27.

"I live for a #Cause not for the #Applause!!!!!!!" she also posted that day. "I like desert, but i prefer the truth... it's sweeter."

'Let them eat cake' #MarieAntoinette,"

Kelly also posted a photo of the cake on Instagram and captioned it with "#EatMyS**t" and "#Hypocrisy."

The 27-year-old Mother Monster was not looking for a fight, it seems. She tweeted Kelly saying, "I didn't know it was your B-day until this afternoon. Meant as a peace offering. Happy Birthday."

Gaga's feud with the Osbournes is nothing new. Kelly called Gaga a "butterface" in 2009 and last year said that Gaga's fans have been telling her to go kill herself, according to The Huffington Post. When Gaga responded in a blog post earlier in 2013, saying Kelly needs to take accountability for being critical of people on her E! show, Sharon called Gaga a "bully" and a "publicly seeking hypocrite and an attention seeker."

On Sunday, however, Sharon seemed move past her feud with Gaga when they hugged on The X Factor. The 61-year-old later tweeted, "Blown away by Lady Gaga's performance and graciousness."

Watch Gaga and Sharon embrace on The X Factor.

Tags: Lady Gaga Kelly Osbourne The X Factor