Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings. With Korea 14 hours ahead, however, she said Mr Kelly may not have fully realised the extent of his children’s new found global fame until he woke up.“It was just fantastic,” said Mrs Kelly. “Robert will be in for a real treat when he wakes up the morning.” This time it was a case of ‘Granny knows best’. In the wake of the star appearance by the children of a South Korean expert during an interview he was giving live on BBC, their grandmother has stepped forward to take the blame.But she also had a word of advice for her son Robert Kelly, whose interview was interrupted in the most spectacular manner possible when Marion, five, and James, nine months, burst into the room while he was on a Skype call – hotly pursued by their mother Jung-a Kim.“Life happens,” said Ellen Kelly. “The lesson is to lock the door!”Mrs Kelly, 72, who lives in Cleveland, Ohio with her husband Joseph, explained that the children may have thought their father was talking to her, as they are familiar with using Skype to stay in touch with their grandparents.Mr Kelly, an associate professor of political science at Pusan National University in Busan, South Korea, was being asked about the impeachment of the country’s president Park Geun-hye, when Marion and James made their impromptu appearance – now shared by millions online.His mother said: “Robert usually Skypes with us from his home office, which is where he did the interview.“The kids probably heard voices coming from the computer and assumed it was us. It was just hilarious.”She added, somewhat hopefully perhaps: “I just hope that he gains recognition for his expertise rather than for this – as great as it all is.”The first Mrs Kelly heard of the incident was when her sister told her. She naturally phoned her son, who admitted to being a bit “embarrassed”.