JK Rowling told thousands of fans at New York's Carnegie Hall that the head of Harry Potter's school was not only gay but also fellow wizard Gellert Grindelwald.

"Dumbledore is gay," she said, adding he was smitten with rival Gellert Grindelwald, who he beat in a battle between good and bad wizards long ago. ""Falling in love can blind us to an extent," she explained to stunned readers, who cheered the news, who had obviously forgotten they were talking about a fictional world run by child wizards."