John Travolta teaches Jimmy Fallon his iconic Grease dance

John Travolta taught Jimmy Fallon his "four corners" Grease dance when he stopped by his talk show on Wednesday night (13Jun18).

Wednesday marked the film's 40th anniversary, with the New York premiere of the beloved musical taking place on 13 June 1978.

John, who starred as the hit movie's uber-cool leading man Danny Zuko, was promoting new film Gotti on The Tonight Show, but Jimmy couldn't help but ask about the '50s-set flick.

"We just had a karaoke party the other day for our nieces, and they're probably like 10 or 12 years old, and they're all singing your songs and doing you, doing impressions of you," an excited Jimmy told his guest. "Not only your singing but your dancing... the singing knocked me out, the dancing, the part at the end with Olivia (Newton-John)."

"The four corners," John replied. "Like in Pulp Fiction, I grew up with all these novelty dances. So in Grease, they needed a step for You're the One That I Want at the end. So I said, 'Well, we used to do the four corners, why don't we do that?' So the choreographer said, 'Show it to me', and I did."

Asking if he'd teach him how to do it, the 64-year-old was happy to oblige.

When the house band started to play You're the One That I Want, John and Jimmy held their fingers through their belt loops and made a four-step box with their feet.

"My God, this is unbelievable!" Jimmy exclaimed.