Nicole Kidman may have pulled off the greatest television prank of all time – and it’s taken years for anyone to realise.

The Australian Oscar-winning actress known for her class and poise once tricked late night talk show host Jay Leno into using a very crude Aussie slang term countless times on his show, as he had no idea what the word meant.

Many were surprised the term was in Kidman’s vocabulary.

Kidman was left giggling after she had convinced the host that “crack a fat” meant something far more innocent that its true meaning (relating to male arousal).

Leno then casually dropped the phrase every chance he got according to the star’s close friend, Russell Crowe.

Speaking to Vanity Fair, Crowe recalled the hilarious incident which happened a few years ago.

“She said it (‘crack a fat’) and Jay kept repeating it over and over again, and Nicole realised the hole she’d dug herself into,” Crowe explained.

“Jay kept saying things like, ‘We’ll be right back after this break to crack a fat with Nicole Kidman!’ And that sent Nicole into giggles.”

Crowe and Kidman have been close friends for years, after they met in Sydney many years ago. 

Crowe apparently did a “shoey” (the act of drinking an alcoholic beverage out of someone's shoe) at a party that Kidman had thrown.

“It was at a house party that I threw in Darlinghurst with my then-boyfriend,” Kidman, 53, told News Corp in 2018 of meeting Crowe.

She went on to say their friendship blossomed when they both began working in the US. 

“I have an enormous amount of love and affection for him because we have been friends literally our whole life. It’s an admirable thing when you forge your way through, decade after decade.”

This article originally appeared on Over60.