The 'Oppenheimer' cast are part of an 'Oppenhomies' text group

He said during a panel discussion to promote writer Jada Yuan's book 'Unleashing Oppenheimer: Inside Christopher Nolan's Atomic-Age Thriller' at a home in Brooklyn, New York: "It's like my biggest claim to fame at this point... starting a huge text chain."

The actor, 31, who also stars in hit show 'The Boys', added it started after he had taken an Uber from his Hampton Inn while filming 'Oppenheimer' to a local grocery store, then realised he had no way to get back.

He said: "I'm leaving, I have my cartful of groceries, I'm on my phone and I realize I was very lucky to get that Uber... because there's no Uber.

"So I steal this grocery cart and I'm rolling it down the highway back to the hotel. That's when I was like, 'All right, I need a rental car and maybe we should start a text chain.'"

Jack - the son of A-listers Dennis Quaid and Meg Ryan - ended up renting a mini-van while shooting, adding: "I was a bus driver, essentially."

Co-stars David Krumholtz, Devon Bostick and Olli Haaskivi also stopped by the Brooklyn book party.

Olli said: "I would argue that 'Oppenhomies' is a way of life more than a text thread."

The group admitted their co-star Kenneth Branagh, 63, who played Danish physicist Niels Bohr in Christopher's epic, is not on the chat - but said they

had their own party in July, when the film was released in cinemas.