By Seamus Duff Saturday Night Takeaway hosts Ant McPartlin and Declan Donnelly were left blushing when a guest swore loudly live on air. The presenting duo devastated fans last year when they revealed they were cancelling their ITV show after 20 years. And now the last ever episode has aired – but proving yet again that the show is one hundred per cent live, the stars were left in hot water when a guest on the show blurted out a swearword. The awkward moment occurred during an energetic segment of the show titled Ring My Bell. A screen showed the view from three doorbells of audience members i…