"Helen's character plays my children"s schoolteacher and one of the emotional hearts of the film is when she comes to sleep on the floor of the room where I am with the kids," The Sun quoted Firth, as saying.
"It's very, very quiet and we can't speak too loudly because the kids shouldn't see their schoolteacher together with their dad, for heaven's sake. “There was a camera at floor level because that's where we were then somebody down there broke wind incredibly loudly.
"It was not silent, it was deadly. Then there was this silence, this paralysis in the room. Helen, who was in my arms, asked: 'What just happened?' Some very noble soul put his hand up and admitted that they did it," he added. The scene had to be shot again.