Britain's Prince Charles, Prince of Wales (L) and his wife Britain's Camilla, Duchess of Cornwall (2L) react as they greet British singer Robbie Williams (2R) and US singer Lady Gaga (R) as they arrive to attend the Royal Variety Performance at the Hammersmith Apollo in London on December 6, 2016. / AFP / POOL AND AFP / Niklas HALLE'N (Photo credit should read NIKLAS HALLE'N/AFP/Getty Images)
