What were the Camerons doing at Cornbury music festival?

Here's the Camerons getting into the spirit of summer at the Cornbury music festival in Oxfordshire. The shindig lived up to its "Poshstock" nickname, with attendees from the notorious Chipping Norton set and two of the Camerons' former bezzies out on bail: Andy Coulson and Rebekah Brooks. Not, of course, that there were any "inappropriate conversations". Downing Street denies reports that the PM and his former spin doctor chatted in the VIP area, and Cameron is believed to have left before Brooks arrived. Which raises the question: what's the point of going if you can't see your mates?