The TV presenter, 36, was left visibly surprised after columnist Giles, 52, revealed he had created a winning eight-letter word - that was unfortunately also an innuendo.
Rachel Riley spells nine-letter word MEGABITCH out on the Countdown board dailymail.co.uk - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from dailymail.co.uk Daily Mail and Mail on Sunday newspapers.
Pregnant Rachel Riley stifles a giggle on Countdown as a contestant spells out a rude word dailymail.co.uk - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from dailymail.co.uk Daily Mail and Mail on Sunday newspapers.