Ben Platt: ‘My parents always knew I was gay – I asked for a fog machine at 7’

The ‘Dear Evan Hansen’ actor is the biggest musical theatre star of his generation, and is about to make his major London debut in a tender new musical about queer love. He speaks to Adam White about audience etiquette, (finally!) playing gay on stage, the backlash to the ‘Evan’ movie, and why he decided to speak out about Israel and Palestine