Barbra Streisand and James Brolin are one of Hollywood's most beloved and long-lasting couples, and are still going strong almost 30 years later thanks to one thing: their mattress.

James revealed their unexpected marital secret on the Todayshow on Tuesday, sharing that good sleep is key for their relationship.

"The best investment we've ever made is our mattress," he shared on the show. "And don't misunderstand me. We're both lazy. We love to sleep late."

"We do a lot of our work on the phone, on paper, reading, right next to each other," he added.

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The couple were set up on a blind date in July 1996, and instantly fell for each other. They went on to marry in an intimate garden ceremony two years later, and will celebrate their 27th wedding anniversary in July. The star-studded guest list for their nuptials included Tom Hanks and Rita Wilson, John Travolta and Kelly Preston, as well as screen legend Marlon Brando.

James spilled another secret about their unbreakable relationship on Today's Tuesday episode, revealing that knowing when to give each other space is integral to a happy marriage.

"You learn to take a walk. Both of us, not just me! I just think you gotta say, 'Okay, take a deep breath, take a walk,'" he said. "Because animals do the same thing, you know? Humans do it to each other, animals do it to each other."