'Grease' Reunion: Olivia Newton-John & Didi Conn Perform 'Summer Nights'

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Olivia Newton-John and Didi Conn

The actresses reprise their roles as Sandy & Frenchy on stage for the first time in nearly 40 years.

It was a high school reunion for Olivia Newton-John and Didi Conn in Las Vegas on Saturday night.

The Grease girls, who played memorable best buds and cousins Sandy and Frenchy in the 1978 classic, joined one another on stage at the Flamingo Hotel & Casino during Newton-John's show.

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Wearing black and pink jackets in tribute to their high school greaser girl and Pink Ladies roles, the two sang the famous "Summer Nights" track for the audience.

The Olivia Newton-John: Summer Nights show features an eight-piece band and includes numerous Grease throwbacks, including "Hopelessly Devoted to You" and "You're the One That I Want," as well as Newton-John's single "Physical."

Newton-John's publicist, Michael Caprio, shared this photo on Twitter:

Grease is the love story of 1950s high school students that sing and dance their way through summer romances and cliques.

Though Newton-John and Conn have professionally reunited in the past -- Newton-John joined Grease's John Travolta at a Conn-hosted Sirius XM town hall event -- Grease is the only film the two performed in together. Conn reprised her role as Frenchy in the 1982 Grease 2, which featured Michelle Pfeiffer and Maxwell Caulfield.

Thirty-seven years later, the famous on-screen pals still go together and are hopelessly devoted.

This article was originally published by The Hollywood Reporter.