go bananas
From Longman Dictionary of Contemporary Englishgo bananasgo bananas informalANGRYto become very angry or excited Mum went bananas when I said I was going to leave nursing. → bananasExamples from the Corpusgo bananas• Roy's customers think the council has gone bananas.• Victor will go bananas, and Rachel will think I got laid.• Dad will go bananas when he sees this.