Harry Styles slept on a mattress in Ben Winston's attic for two years.
The 23-year-old singer was looking to move into a property in Hampstead Heath in London, but he asked the film producer whether he could stay at his nearby abode for a short time while the finishing touches were put to the deal for his new house.
Ben explained: "Two weeks later and he hadn't bought his house yet. It wasn't going through. Then he said, 'I'm going to stay until Christmas, if you don't mind.' Then Christmas came, and ..."
Harry - who became a global star during his time in One Direction - actually ended up living with Ben and his wife Meredith for the next 20 months, even though fans of the heartthrob would still gather outside the empty property where he didn't actually live.
Ben told Rolling Stone magazine: "Those 20 months were when they went from being on a reality show, 'X Factor', to being the biggest-selling artists in the world.
"That period of time, he was living with us in the most mundane suburban situation. No one ever found out, really. Even when we went out for a meal, it's such a sweet family neighbourhood, no one dreamed it was actually him. But he made our house a home. And when he moved out, we were gutted."
During that period of time, Ben and has wife would stay awake at night to see who Harry would bring back home with him.
He explained: "That was always what we enjoyed, because we'd be in bed like an old couple. We'd have our spot cream on our faces and we'd be in our pajamas and the door would go off.
"The stairwell was right outside our door, so we'd wait to see if Harry was coming home alone or with people."
Harry insisted he was "always alone" because he was "scared of Meri".
But Ben remembers the situation slightly differently.
He said: "He wasn't always alone, but it was exciting seeing the array of A-listers that would come up and sleep in the attic. Or he'd come and lounge with us.
"We'd never discuss business. He would act as if he hadn't come back from playing to 80,000 people three nights in a row in Rio de Janeiro."