Phil Donahue and Marlo Thomas were married 44 years. Their top 3 marriage secrets

Phil Donahue and Marlo Thomas were married for 44 years, and she was by his side when the talk show host died at home on Sunday, Aug. 18, at age 88.

"I lost my sweetheart last night," Thomas wrote on Facebook on Monday, calling Donahue her "beloved Phillip." She included one of her favorite photos of the couple taken when they were younger and on vacation.

The couple famously fell in love on live television.

“It was kind of love at first sight,” Thomas recalled on “Late Night with Seth Meyers” in 2021. “Something chemical happened.”

They initially kept their marriage out of the limelight, but became more public about it and their relationship advice in recent years, even hosting a podcast about marriage success in 2021 titled, "Double Date with Marlo Thomas & Phil Donahue."

How did Phil Donahue meet Marlo Thomas?

The couple clicked when she was a guest on his talk show in 1977.

It was actually the second time they met, Donahue recalled in the couple's 2020 book, “What Makes a Marriage Last: 40 Celebrated Couples Share with Us the Secrets to a Happy Life.”

The first time was in 1972 when Thomas was promoting a TV special and came to Dayton, Ohio, where his show was based at the time. She was an actor, author and social activist best known for the TV series “That Girl” and her children’s book series, “Free To Be...You & Me.”

Donahue found her beautiful, bright and "the perfect guest," he wrote, but her appearance wasn't as memorable as the next time they met.

Five years later, Thomas was back on his show, this time at the Chicago studio. Donahue was recently divorced. She was single.

A clip from "Donahue" posted on Thomas’ YouTube page shows the couple exchanging smiles and warm glances as they talk. “Instant chemistry!” Thomas wrote in the caption. “We were flirting like mad,” she told Meyers.

“You are really fascinating,” Donahue told her, taking her hand.

“You are wonderful,” Thomas responded, placing her other hand on his. “You are loving and generous, and you like women and it’s a pleasure. Whoever is the woman in your life is very lucky.”

They had dinner afterward, and he told her he doubted he’d ever marry again. She liked his mindset because she wasn’t looking to get married either, Thomas wrote in AARP magazine. "I was the girl who never wanted any part of it," she wrote in their book.

Love blossomed because they didn’t feel the pressure to say, “I do."

“Had Phil and I been younger, we might have been more impatient and missed each other. But being older — me in my late 30s, Phil in his early 40s — we trusted our hearts and made the effort,” she wrote.

“For many, love really is better the second time around, but for me, the first time has been just fine.”

After long-distance dating — he lived in Chicago, she in Los Angeles — the couple married in 1980.

What’s the age difference between Phil Donahue and Marlo Thomas?

There was a two-year age difference. Phil Donahue was born in December 1935 and Marlo Thomas was born in November 1937.

Did Phil Donahue and Marlo Thomas have any children?

No. Donahue had five children from a previous marriage: four sons, Michael, Kevin, Daniel and James; and one daughter, Mary Rose.

Thomas became stepmom to his kids, writing that she decided to be their friend rather than a mom in the traditional sense.

Their secrets to marriage success

Thomas said the secret to keeping their long marriage strong could be summed up by “the three L’s: Love, listening and lust,” she told People in 2023.

“You have to listen and then you’ll know what the other person is really thinking and going through. You have to love each other. And without lust, you don’t have anything,” she explained.

In 2015, Thomas told TODAY that she and Donahue didn’t critique each other’s projects — another secret to their long-lasting relationship.

"The secret of good communication: Screaming helps," Donahue joked in an interview with AARP. "At least you get to know whether the person you're screaming at is listening. Then go in the other room and count to 10."

Through the years, you learn that everything is not that big of a deal, Thomas added.

In 2020, the couple wrote their book, “What Makes a Marriage Last.” It was the first time they worked on a shared project, breaking an “ironclad rule of our marriage” to not work together, they wrote in AARP magazine.

It happened after Donahue and Thomas were shaken when a friend told them she was divorcing her husband of 28 years.

“Where did they go wrong, we wondered, and more to the point, where did we go right?” the couple wrote.

Their book featured advice from famous couples who had been married 15 years or more, including Jimmy and Rosalynn Carter, Kyra Sedgwick and Kevin Bacon, and Joanna and Chip Gaines.

The lessons: Gratitude, trust, humor and occasional therapy are among the keys to long-term marriage success, Donahue and Thomas found.

You have to want the marriage to last, Donahue told TODAY with Hoda & Jenna. Accommodation — not compromise or trying to change somebody — is the most important thing in a marriage, Thomas added. Look at your spouse, realize who they are and let them be, she advised.

"Our biggest lesson is: there is no one secret to a lasting marriage, there are a million secrets," the couple wrote at the end of the book.

"So keep looking for them. Because the longer you look, the more you’ll discover reasons to stay in it."

This article first appeared on TODAY.com. More from TODAY:

• 43 budget-friendly gifts under $50 for everyone on your list
• Fore-ty golf gifts that are sure to be on par, starting at $10