Poison in the Ivy
The gathering was secreted in an upstairs room, but their arrival caused comment among the nobs dining downstairs. (Guests, incidentally, were forbidden from opping downstairs to go celeb-spotting).
One quartet of well-heeled diners in particular overhead one journo asking for the "private function".
"Private function? Is it a pop group?" one asked excitedly. "No, it's the National Association of Head Teachers."
"Headteachers? Good for them - and why shouldn't they eat at The Ivy?" was the memorable response.