that’s news to me!
From Longman Dictionary of Contemporary Englishthat’s news to me!that’s news to me!spokenSURPRISED used when you are surprised or annoyed because you have not been told something earlier ‘The meeting’s been cancelled.’ ‘That’s news to me!’ → newsExamples from the Corpusthat’s news to me!• The meeting's been canceled? That's news to me.