Sarah Ferguson was left irritated as the crowd spoke over her at the amfAR charity gala at Cannes Film Festival. The 64-year-old philanthropist and author – who was married to Prince Andrew, also 64 – was a special guest at the bash on May 23, and was there to shine a light on the genius scientists behind AIDS research and HIV prevention. A painting of the late Queen Elizabeth II – Sarah’s former mother-in-law – was auctioned off for more than £400,000 for the cause, but Sarah was forced to call out the rowdy guests and accused them of just being there to “party” and not to applaud their outst…