Bradley Cooper was shocked when he was named PEOPLE’s Sexiest Man Alive. The 49-year-old star received the title back in 2011, and according to his close friend Dax Shepard, Bradley initially thought the magazine was “pulling a prank” on him. Dax, 49 – who is married to actress Kristen Bell – said on the ‘Armchair Expert’ podcast: “He genuinely thought when he was named Sexiest Man Alive that it was a bit – that PEOPLE magazine was pulling a prank. He thought they were f****** with him. “I’m like, ‘You handsome son of a b****. You have no idea how horny everybody is for you.’” Dax believes Bra…