America fell in love with John Travolta and Olivia Newton-John in 1978 when the pair played the roles of playboy Danny Zuko and naive exchange student Sandy Olsson in the iconic musical Grease.

Despite their electrifying chemistry, that was the first and only time that Travolta and Newton-John have appeared in a film together.

Travolta went on to star in a number of critically-acclaimed and award-winning films, including Pulp Fiction, Hairspray and Get Shorty. Newton-John also took up numerous acting gigs, but she had more success with her music career. She had a string of number one hits and won four Grammy Awards.

Still, the on-screen couple remained good friends all these years.

"John and I have stayed in touch, and in 2012 we made a Christmas album and sang  a duet called "I Think You Might Like It," which was a sort of sequel to "You're the One That  I Want" by the same writer, John Farrar," Newton-John told The Telegraph last year.

She also commented on her friendship with Travolta in another interview a few years prior.

"Friendships like that are to be treasured because it's rare to find it once in a working lifetime. I found it twice, with Cliff [Richards] and John Travolta," Newton-John said in an interview a few years ago.

Over the years, the pair have had a couple of mini reunions - from appearing on The Ellen DeGeneres Show to performing an impromptu duet on stage during Newton-John's tour.

This week, Travolta and Newton-John have once again proved that they're hopelessly devoted to each other as they enjoyed another mini reunion at an event in Los Angeles.

Newton-John, 69, and Travolta, 63, attended the G'Day USA event in Los Angeles on January 27th, and took the opportunity to catch up.

The pair were photographed side-by-side before the event and while they were on stage. Travolta is seen sporting a new look: a gray beard and hair; while Newton-John looked beautiful despite her recent battle with cancer.

Newton-John announced in May 2017 that her breast cancer had returned and metastasized to her lower back. In the announcement posted on her Facebook page, she was seeking "natural wellness therapies" and "a short course of photon radiation therapy" to fight the cancer.

Three months after the shocking revelation, the "Physical" singer shared a video message reassuring fans that she was "feeling great" and on the road to recovery.

As soon as news of her illness reached Travolta, the actor shared the sweetest message.

"Olivia has always been an incredible human being and an inspiration to millions of people," he told People. "If we all put our intentions for her to get through this "“ I know her so well "“ she will feel it, and it will support her. We love her and she loves us."

Last year, Newton-John also got fans excited about the possibility of a Grease reunion of sorts to commemorate the 40th anniversary of the hit musical.

"We are thinking up ways. Nothing to announce yet," Newton-John teased. "Forty years anniversary of Grease, which I can't believe. Time goes so fast. It is so exciting."

We can't wait to see what Newton-John and Travolta have in store for us!

Are you a Grease fan? Let us know!