Michael J. Fox didn't realize he'd be sitting next to Princess Diana at the London world premiere of the movie

Michael J. Fox was really that close to being on a date with Princess Diana!

The iconic actor stopped by Wednesday's Tonight Show where host Jimmy Fallon did his best to clear up any rumors about Fox.

"The first one: you once watched Back to the Future while sitting next to Princess Diana?" Fallon asked.

"It’s true, the world premiere in London," Fox, 59, said of the 1985 screening with Princess Diana and then-husband Prince Charles. "She was sitting next to me and she sits down and I looked at her and realized I’m one fake yawn and outstretched arm from being on a date with her."

But it wasn't all that great, since Fox quickly found himself in a bathroom emergency.

"But then what happened was the movie started and all of a sudden I had to go pee," Fox recalled. "So then I’m sitting there, I’m dying. I can’t say anything to her and I can’t walk away from her cause I can’t turn my back on her. So what could’ve been the greatest night of my life was a nightmare."

Thankfully, the late princess seemed to enjoy the movie and Fox remembered her laughing a few times.

Fox ended up finding the love of his life in wife Tracy Pollan. The two have now been married for 32 years and their love has only grown deeper.

“Every day we have something we laugh about for a good two minutes,” the actor told PEOPLE about Pollan in a cover story earlier this month.

“The kind of support she gives me, I feel like a husband, a father and a friend first, and then somewhere way down the line, I’m someone with Parkinson’s," said Fox.

Fox, who was diagnosed with Parkinson's disease in 1991 and went public with the diagnosis in 1998, met Pollan in the summer of 1985, when she auditioned for Family Ties. Though she departed the show after one season, they reunited for the film Bright Lights, Big City in 1987. He asked her to lunch, they started dating, and they wed a year later.

Princess Diana, Michael J. Fox
Credit: Tom Wargacki/WireImage; Fox Photos/Hulton Archive/Getty

In the three-plus decades that they've been married, Fox has leaned on Pollan and their three children — son Sam, 31, twin daughters Aquinnah and Schuyler, 25, and daughter Esmé, 19 — for support as he navigates his ongoing health battle.

"My kids are adults now,” the Back to the Future star said. “I never held back about my situation before, but now I really can speak plainly.”

“People don’t believe me, but I love life," said Fox, whose fourth memoir No Time Like the Future is out now.

"I love being with my family. I love being with Tracy," he said. "I love that I don’t do a lot of useless stuff that I used to do, because I don’t have the energy or the time."