Grease is the word! The high school romance musical is a cult phenomena, with its songs and fashion styles still resonating through the world today. But behind the leather jackets and greased-up hair, lots of naughty shenanigans were going on away from the cameras.

As they celebrate 40 years since the release of the hit musical film, the cast have made some pretty amazing revelations of just what went on off set. But hang on a second, weren’t these people only kids? They must be kids because they played high-schoolers? Well it turns out this wasn’t the case! At the time of filming, Olivia Newton-John (aka the blonde-bombshell Sandy) was actually 28 years old! Her romantic interest, John Travolta, was a tad younger than her at 23.

It is claimed that the two actors had to pass ‘crow’s feet tests’ to make sure they looked young enough to play teenagers. If their facial lines were visible in close-up shots, they would not have been given the roles of the high school lovers. So with the cast being older than their on-screen characters, there was much debauchery going on behind the scenes. These involved things like ‘rocking trailers’ and ‘spiked brownies.’

It is said that Jeff Conaway, who died in 2011 aged 60 and played Kenickie in the 1978 film, was said to be quite the ladies man on set. He reportedly had a very big crush on Olivia Newton-John. But Barry Pearl, who played T-bird Doody, said Conaway spent much of his time ‘seducing the extras’ whilst also keeping his eye on Liv.

‘We used to joke all the time because his trailer at lunchtime was really rocking,’ he said. ‘He made out like a bandit.’

And it seems that Conaway wasn’t the only big hit with the ladies. Dinah Manoff, who played Pink Lady Marty, has spoken of John Travolta’s allure on set. Being the main man and playing Danny Zuko, there’s no surprise that all of the ladies were fawning over him.

‘You couldn’t fail to have the biggest crush in the whole world on him. He was radiating so much talent and energy. I just started stuttering around him,’ she said ahead of the anniversary. ‘Think about that moment he turns around in the film for the first time: you see that face and everybody just gasps.

‘That’s how it was. Really jaw-dropping.’

Didi Conn, who played the beauty school drop out Frenchie, remembers a particular time at the wrap party where everyone was high. She said: ‘I don’t even remember the wrap party because somebody made some brownies. There was something in it! I won’t mention names… I just remember laughing a lot!’ It seems like sex, drugs and rock and roll really did go down during filming.

Didi has also revealed that cast members had to fight not to pass out from the heat because all the windows were kept closed during filming. There was a very good reason for this. The school that masqueraded as Rydell High, Venice High School in Los Angeles, was situated next to a pork plant.

Didi said: ‘It was so smelly, noisy and so very, very hot but everybody was just having fun, dancing and trying new things — you had to or you’d faint from the heat.’ We’ll never look at the movie the same!

It would certainly be interesting to go back in a time machine to see just exactly what it was like on set. With all those young-ish people in such a small and hot environment, we’re not surprised that they were doing the dirty when they got back to their trailers.