The 38-year-old actor was reduced to a giggling mess as he joined the talk show host in a game of 'Three-Word Stories' on 'The Tonight Show'.

Benedict - who recently got engaged to his long-term girlfriend Sophie Hunter, 36, - could barely hold himself together as he tried to get Jimmy to say the word "booty".

The game - which involves a mystery word with the first player having to use three words to guide the second player to say the mysterious phrase - started off nicely as Jimmy got Benedict to say the word "unicorn".

However, when the time came for Benedict to get Jimmy to say "booty", things turned silly.

The 'Imitation Game' star kicked things off by saying: "You've got to shake..."

To which Jimmy replied: "Shake it off."

Benedict then said: "A beautiful big..."

Prompting Jimmy to quip: "Kim Kardashian's butt!"

Despite all the laughter, Benedict persevered by adding: "Makes lots of..."

As Jimmy joked: "Money for Kanye."

After the giggling about Kim's impressive posterior died down, Benedict went on to discuss his infamous photobomb moment with U2 at the 86th annual Academy Awards in March, revealing it was inspired by one of his close friends.

He said: "I've got a friend Helen who is a huge, life-long fan (of U2), I mean as am I am, but she's like, 'Oh my God they really are [the] soundtrack of my life, please, please, get a photo with them. And I thought, 'Perfect moment for it.'"