The transatlantic difference can, perhaps, be explained by the difference in what makes US and UK sitcoms tick. In America, the comedy usually comes from characters who try, endearingly, to achieve normality despite their foibles – as true for the gays in Modern Family as it is for the geeks in The Big Bang Theory. Over here, sitcoms rely on characters clinging on to their self-aggrandising delusions despite the normality all around them – as true for Sue Perkins as it was for Basil Fawlty or David Brent. But being closeted is tragic, not comic. And in modern Britain, it also defies credibility.