'Grease' star reveals John Travolta had a crush on Olivia Newton-John during filming

Grease actress Didi Conn has said she is still close friends with former co-star Olivia Newton-John and has some secrets of the stars to share.

40 years after the hit movie was released, Conn, who played wannabe beautician Frenchy in the 1978 film opposite Newton-John as Sandy, confirmed the pair are still friends and she often goes to her gigs.

Everyone can agree that Danny Zuko and Sandy Olsson were the perfect couple in Grease. The movie tells the story of a high school couple who struggle to make their relationship work after they fall madly in love with one another over the summer.

In the beloved film, Olivia Newton-John famously played good-girl Sandy and John Travolta portrayed Danny, a grease-loving bad boy. According to Daily Mail, Didi revealed that John was attracted to Olivia during the movie's shoot.

Didi also revealed that the film's 40th-anniversary edition includes an alternate ending for the movie where Danny gives Sandy a big kiss in the final car scene, as opposed to the original version where they only kiss at the beginning of the movie.

According to Didi, the hit musical was also supposed to have a sequel called Summer School which followed Danny and Sandy's romance after graduation. John and Olivia agreed on making the second movie right after the wrapped Grease.

However, Paramount was not so sure that the movie was going to be a success. In fact, they thought the film would be a failure and when it became the huge movie hit on charts, the director started making arrangements for the sequel but Travolta and Newton were not available anymore.

Conn reckons the film has been so popular over the years because it is about first love, the first car, the first break-up, and the first career disappointment, at least for her character.

The cast had so much fun shooting that the 66-year-old joked about having a cloudy memory at the Grease wrap party after her co-star Stockard Channing, who played Rizzo, made the cast "special brownies." That most have been a crazy party.