Natalie Portman and husband Benjamin Millepied 'working things ...

Thor star Natalie Portman and her ballet dancer husband are reportedly fighting to save their marriage after she discovered he had been having an affair with a woman 20 years his junior.

French outlet Voici claimed this week that Portman’s partner Benjamin Millepied, 45, had been briefly involved with 25-year-old French climate activist Camille Etienne.

Etkienne is a friend of Greta Thunberg’s and is a French climate activist, writer and filmmaker.

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Voici said Portman discovered the liaison in March.

Natalie Portman with her husband Benjamin Millepied at a Thor: Love And Thunder screening last year. Credit: Getty Images

However People magazine reported Friday (local time) that the affair was brief.

“It was short-lived and it is over,” a source told the US outlet.

“He knows he made an enormous mistake and he is doing all he can to get Natalie to forgive him and keep their family together.”

Natalie Portman as Mighty Thor and Chris Hemsworth as Thor in Marvel Studios' THOR: LOVE AND THUNDER. Credit: Jasin Boland/Jasin Boland

The couple have two children — their son Aleph, who turns 12 this month, and six-year-old daughter Amalia.

The 41-year-old Portman has been with Millepied since they met on the set of Portman’s 2010 movie Back Swan, in which she played a ballet dancer.

Millepied was the choreographer on the production and taught Portman her character’s moves.

They married in the Californian coastal town Big Sur in 2012 and celebrated their tenth wedding anniversary last year.

PARIS, FRANCE - SEPTEMBER 25: Camille Étienne attends the Global Citizen Live on September 25, 2021 in Paris, France. (Photo by Kristy Sparow/Getty Images For Global Citizen) Credit: Kristy Sparow/Getty Images For Global Citizen

Page Six reports that Millepied was nowhere to be seen last month while Portman attended the Cannes Film Festival for the premiere of her film May December.

However the outlet does note the pair were seen together at a Beyonce concert in Paris on May 26 and then kissing at dinner a few days later.

Natalie Portman with her husband Benjamin Millepied at the 2021 round three NRL match between the South Sydney Rabbitohs and the Sydney Roosters at Stadium Australia. Credit: Cameron Spencer/Getty Images

“They have not split and are trying to work things out. Ben is doing everything he can to get Natalie to forgive him. He loves her and their family,” a source told Page Six.

Portman and Millepied spent some months in Australia in 2021, while Portman was filming the Marvel movie Thor: Love And Thunder in Sydney.

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