Despite Gaga burying the hatchet with Sharon Osbourne on The X Factor over the weekend, Kelly wasn't so quick to settle her feud with the singer and rejected the birthday cake she was sent by Gaga as a peace offering.
At the time (27 October), Kelly called the kind gesture "hypocrisy" and added: "Not to be ungrateful but why would you send me a birthday cake via my MOTHER in a country half the [world] away? #JustSendItToME #LoveNotWar."
However, it appears that 29-year-old Kelly has now had a change of heart and apologised to Gaga in the early hours of this morning (29 October), explaining that she had "acted like a child".
@ladygaga I acted like a child last night. Just not into publicity stunts call me & we will end this like adults I dont want 2 fight anymore— Kelly Osbourne (@KellyOsbourne) October 29, 2013
Taking to Twitter, Kelly said: "@ladygaga I acted like a child last night. Just not into publicity stunts call me & we will end this like adults, I dont want to fight anymore."
Gaga is yet to respond to Kelly's latest tweet, but it looks like the pair, who famously fell out over the years after making a series of remarks about one another, both want to bury the hatchet.
After Gaga sent Kelly the birthday cake on Sunday, she defended her actions at the time, saying: "@KellyOsbourne I didn't know it was your B-day until this afternoon. Meant as a peace offering. Happy Birthday."
Listen to the audio of Lady Gaga's song 'Venus' here: