In fact, it’s fair to say that the connection between the pair intensified beyond anything either of them had anticipated. Last month, she confirmed that her fledgling star was now also her fiance.
Having cast in October last year, they worked together on accent and musical technicality before shooting began on location in Liverpool and London this February. It was then that their working relationship became something far more personal.
“I did have a ‘My God, he’s fantastic’ moment,” she smiles. “It was when we were in Liverpool, I remember shooting this one scene and just thinking that he so embodied the Lennon as I wanted it to be. I remember just looking through the camera and thinking, OK, this is going to be great. And he continued to be, thank God.
“That was in terms of the film,” she adds. “The personal moment came later when we’d almost finished filming.” At 42, and with two young children by former husband art dealer Jay Jopling, Sam suddenly found herself the subject of tabloid gossip rather than broadsheet arts analysis.
Media attention was nothing new; she and Jay courted it to a certain extent when they were the darlings of the Brit art scene with shock tactics and celebrity subjects (her one-hour video of a sleeping David Beckham was commissioned by the National Portrait Gallery). An A-list circle of friends counted Elton John, Guy Ritchie, Jude Law and Kate Moss among their number.
Her fight against colon and breast cancer, in 1997 and again in 2000 when she underwent a mastectomy, had been well documented, too.
But this was previously uncharted territory.
Neither particularly defensive nor candid on the subject, Sam is nevertheless good-humoured in her acceptance that a 23-year age gap – especially when the woman is older – will inevitably raise eyebrows.
“Yes,” she smiles, “I mean I try not to pay too much attention to it, but people are always interested in other people’s relationships, especially out of something high profile like a film.
“I think, if I’m honest, we did hope to get away with it,” she adds, laughing at an obviously hopeless cause. “But maybe everyone will just get bored eventually.”
