Riley, famed for her role on the show, finished spelling out words during a letters round of the show before host Nick Hewer asked Kovalev and Susie Dent for any other suggestions.
Strictly Come Dancing star Kovalev, who has been dating Riley since 2016, admitted that he did have a seven letter word to spell out – BUMHOLE.
Amused Riley shared an image of her standing in from of the board, captioning: “Off the edit room floor! One day I’ll grow up enough not to laugh at this, but for now, it’s officially funny.”
Off the edit room floor! One day I’ll grow up enough not to laugh at this, but for now, it’s orofficially funny 😂🤣 pic.twitter.com/vpFSjPA0fG— Rachel Riley (@RachelRileyRR) 23 April 2018
“Can’t take @PashaKovalev anywhere . This was supposed to be the clean version of the show!” she added in another tweet, sharing the video clip.
The professional dancer had said: “Yes, there is a word there that consists of seven letters. Um... and it's bumhole.”
While Dent explained: “the only thing I would say, having looked it up in the big Oxford English Dictionary, is it's been in the dictionary since 1611, or at least it's been recorded since 1611.”
Riley is no stranger to standing in front of rude words, having previously caught the giggles at “a**wipe” earlier in the year.
Riley and Kovalev first met back in 2013 when the presenter appeared on Strictly.
Countdown airs weekdays at 2.10pm on Channel 4.