Joaquin Phoenix had to leave the set of his movie ‘Her’ after getting the giggles during a phone sex scene with Scarlett Johansson. In the 2013 film, the Oscar-winning actor played a lonely man who falls in love with an artificially intelligent virtual assistant – voiced by Scarlett – and in one scene he had to respond to recordings of her acting out an orgasm and the actress has revealed the movie star couldn’t keep a straight face, During an appearance on Dax Shepard’s ‘Armchair Expert’ podcast , Scarlett explained: “We tried to get through one take, and he was, like, losing it. He left the …