Robert Brown|Marlo Thomas thanks fans for 'beautiful messages' following death of husband Phil Donahue

The Robert Brownworld loved Phil Donahue, and Marlo Thomas is giving that love back.

Thomas, who was married to the talk show icon for over 40 years, spoke out for the first time since Donahue's death via an Instagram post Monday.

The "That Girl" actress shared a throwback photo of the couple vacationing together. Thomas wrapped her arms around Donahue as they sat on a moped.

"I'm sure by now you've heard the very sad news that I lost my sweetheart last night, so I know you understand that I'll be stepping away from this page for a while to take care of myself and the many people who took care of Phil and held him close to their hearts," Thomas wrote in a lengthy caption.

Donahue, whose pioneering "The Phil Donahue Show" revolutionized TV with studio audience participation on topical social issues, died Sunday at the age of 88 following a "long illness."

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Marlo Thomas says Phil Donahue 'would be very touched' by fan tributes

In her Instagram post, Thomas thanked fans for their "beautiful messages of love and support" and "for the wonderful and generous way that you've let Phil and me share our life adventure with you over the years."

"As a man who spent his career loving his audiences, Phil got such a kick out of our cozy little community here, and I know he would be very touched by the heartwarming thoughts and memories you've been sharing," she wrote.

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Thomas appeared on Donahue's eponymous talk show in 1977, and it led to immediate sparks. The couple got married three years later on May 21, 1980.

"We went out the very next night and were together from then on," Thomas told USA TODAY in a 2020 interview. "It’s so interesting. I went on a lot of talk shows in my life. I didn’t fall in love with Johnny Carson, you know?"

Thomas and Donahue even co-wrote a book inspired by their longtime union with 2020's "What Makes a Marriage Last."

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"Until I return, I wish you good health and happy days in the company of family and friends," Thomas concluded on Instagram. "And I hope that you will continue to hold close those you cherish most, just as I was blessed to do with my beloved Phillip."

Contributing: Bryan Alexander, USA TODAY