Celebrities often specialise in odious behaviour to other celebrities. Back-handed compliments, passive aggression and faux concern are the standard tools of the celebrity frenemy. But Lipgoss's pet hate is when a celebrity pretends that they've never heard of another celebrity.

In this age of Wikipedia, you can become an instant expert on someone you had never heard of five minutes earlier. So the only reason for faking ignorance is to make yourself sound high above Kardashian territory.

"Sienna who? I'm sorry, I only associate with the likes of Sir Ian McKellan and Dame Judi Dench. And I'm afraid I don't own a television, have minions to read the internet to me, and wouldn't dream of sullying my fingertips with a flimsy tittle-tattle magazine. Fnarr, fnarr."

So we're disappointed that the grande dame of crazy British dressing, Vivienne Westwood, resorted to this petty tactic when presenting an award to Emma Watson, Harry Potter megastar and current darling of the British fashion scene.

All she needed to do was smile and say, "Nice frock, sister." Instead she rambled on, to the tune of, "I was supposed to welcome and to announce the winner of the Style Icon. They said Emma Watson. I said, 'Who is Emma Watson?' I never watch television, I don't read fashion magazines. They said she used to be in Harry Potter, and I said, 'I've never seen Harry Potter.' They said in the movies they have this girlfriend called Hermione and I said, 'Oh.'"

Emma Watson, being about a tenth the age of Viv, could easily say, "Who let this crazy bag lady in? SECURITY! Oh, I see. Sorry, but Vivienne WHO?"