Ricky Gervais has filmed a guest slot on the 40th anniversary edition of Sesame Street. The episode doesn't air until November in the US, but here are some outtakes of him singing a song called Set Your Piggies Free with Elmo. The red monster doesn't take too well to the comments about his pyjamas. "It's called acting, Mr Gervais. Acting." That's him told, then.