Cate Blanchett, centre, president of the festival jury, poses with fellow members, from left, Kristen Stewart, Léa Seydoux, Ava DuVernay and Khadja NinINDEPENDENT PHOTO AGENCY SRL/ALAMY LIVE NEWS

On the red carpet the woman nervously tugged at the silver slivers of material barely covering her nipples, readjusting her dress as the paparazzi snapped. "Who is she?" I asked somebody. The reply: "Justin Bieber's ex." In the first week at the Cannes film festival I saw starlets walk red carpets in various states of undress, obligingly posing for photoshoots to flog films based on their looks. During the day I saw women pose in skimpy outfits on La Croisette, re-emerging at night wearing even less and accompanied by fully dressed men.

I went to after-parties where I watched girls teeter in scraps of fabric, saw perma-tanned septuagenarians grab nubile hostesses and heard delegates swap stories about their sexual conquests. I walked around at night…