Kelly Osbourne has called a truce with Lady GaGa.

The star reached out to her long-time rival after her online outburst on Sunday (27.10.13) when Gaga attempted to quash her feud with the Osbournes by presenting showbiz matriarch Sharon with a birthday cake to mark her daughter Kelly's 29th birthday.

Gaga posed with Sharon and the cake after performing on 'The X Factor' UK and a furious Kelly went on a Twitter rampage upon seeing the picture, telling the 'Applause' singer ''eat my sh*t'' and branding her a hypocrite.

Kelly has since taken to Twitter to apologise, saying: ''@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 (sic)''.

It appears the purple-haired star has agreed to forgive and forget after Sharon - who hugged it out with Gaga on Sunday night - appeared to do the same.

Sharon tweeted on Sunday: ''Blown away by Lady Gaga's performance and graciousness.''

The Osbournes have been involved in a bitter feud with Gaga for months, with Sharon branding the eccentric singer - whose Born This Way Foundation campaigns against bullying - a ''publicity-seeking hypocrite'' for letting her fans send threatening messages to her daughter Kelly after she blasted Gaga's 2012 Grammy Awards outfit.

The pop superstar has yet to publicly respond to Kelly's peace offering, but graciously told her followers - who she calls her Little Monsters - not to respond to Kelly's initial messages with angry words.

She posted: ''Monsters, please just focus on the positive of tonight's performance and do not send any hateful messages. I don't support it. #SpreadLove''.