Bopperella! Fonda, 69, gives Lohan, 20, a workout on the dance floor

But that didn't stop Jane Fonda taking to the dance floor with her co-star Lindsay Lohan, nearly 50 years her junior.

Jane, who famously played the title role in the 1968 science-fiction sex-romp Barbarella, was at the China Club in New York celebrating the premiere of Georgia Rule with Lindsay, 20, who plays her granddaughter in the movie.

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Out on the town: Jane and Lindsay strut their stuff

By chance, they were dancing to a risque rap song by hip-hop artist Mickey Avalon featuring the line 'Do the Jane Fonda' - not, apparently, a reference to the actress's workout videos.

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Jane shows co-star Lindsay a few moves - despite the almost 50 year age gap

"I didn't know it referred to a sexual act. I thought it meant working out," Jane later told chat-show host Larry King.

"All I could hear was 'do the Jane Fonda'. I didn't hear all the subtleties because I was busy dancing."

In the new film, Jane's character has to straighten out her wild child granddaughter, a role that some might say suited Lindsay down to the ground.

The young star, a regular at Los Angeles' most fashionable night spots, was rebuked by the movie makers after repeatedly taking days off sick while filming.

Morgan Creek Productions chief executive James G. Robinson wrote to her saying: "We are well aware that all-night heavy partying is the real reason for your so called 'exhaustion'.

"We refuse to accept bogus excuses for your behaviour. You have acted like a spoiled child."

And Jane said in an interview last week: "She was late a few times and I shouted at her. Afterwards, they told me she'd said, 'Barbarella just yelled at me!'"

Plainly, they had made up at the premiere party and Lindsay insists: "There were no problems."