Add Tip Toe to your watchlistSat in the penthouse suite of a chi-chi London hotel on a sunny Saturday, Alan Cumming is halfway through explaining how hedonism and activism aren’t mutually exclusive when he suddenly stops mid-sentence and stares at his hand. For a moment, he looks confused – then suddenly relieved. “I wondered what was wrong with my finger – it’s green. But I’ve got green eye make-up on, haven’t I, from this morning,” he says. “A…