Michael Douglas and Catherine Zeta-Jones are paying tribute to a legend.

Douglas lost his father, Hollywood icon Kirk Douglas, in February at the age of 103.

Now, in remembrance of the "Sparticus" star, Douglas and Zeta-Jones have shown him a little love on social media.

For her part, Zeta-Jones shared a black-and-white photo of Kirk planting a kiss on her cheek as she leans over her shoulder with her eyes closed.

MICHAEL DOUGLAS, CATHERINE ZETA-JONES REMEMBER THE LATE KIRK DOUGLAS: 'THERE WASN'T ANYONE LIKE HIM'

"Missing you every day," she wrote in the caption. "Happy birthday Pappy."

Kirk Douglas (left), Catherine Zeta-Jones (center) and Michael Douglas (right). Michael and Catherine paid tribute to Kirk on social media on what would have been his 104th birthday. (Photo by Taylor Hill/FilmMagic)

Kirk Douglas (left), Catherine Zeta-Jones (center) and Michael Douglas (right). Michael and Catherine paid tribute to Kirk on social media on what would have been his 104th birthday. (Photo by Taylor Hill/FilmMagic)

The "Chicago" star, 51, added a pink and red heart emoji to the message.

Douglas, 76, shared an audio message over a slideshow of throwback photos of himself and his old man.

"The best advice my father gave me was: 'Whatever you do, you do it to the best of your ability," the Oscar winner said. "You leave that job knowing that you couldn't have done any more."

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He added: "And then, screw it, walk away. You've done the best. Don't look back."

The slideshow of images concluded with a written message.

Kirk Douglas (left) and his son Michael Douglas (right). Kirk died at 103 earlier this year. (Photo by Michael Buckner/Getty Images)

Kirk Douglas (left) and his son Michael Douglas (right). Kirk died at 103 earlier this year. (Photo by Michael Buckner/Getty Images)

"Happy birthday Dad. I miss you," it read. "Love, Michael."

The pair of actors opened up to Entertainment Tonight earlier this year to reflect on the late star.

"There's another generation, that was the great generation, post-World War II … and Dad was one of kind," Michael Douglas said.

At the time, the couple was raising money for a fundraiser, "We All Play Our Part: A Benefit for MPTF," from the Motion Picture & Television Fund, which benefits its COVID-19 Emergency Relief Fund, according to Entertainment Tonight.

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As for what Kirk would think of their efforts? Douglas said he believes his father would be "very happy."

"I know he takes particular pride -- not so much in whatever I worked with and I'm doing with the Motion Picture Television Fund -- but I know he loves Catherine [and] the work that she's doing," he said.

Kirk Douglas with his daughter-in-law Catherine Zeta-Jones. (Photo by Frazer Harrison/Getty Images for AFI)

Kirk Douglas with his daughter-in-law Catherine Zeta-Jones. (Photo by Frazer Harrison/Getty Images for AFI)

The "Kominsky Method " star continued: "He always used to tease me. We would call him up and he would be like, 'Enough with you, let me talk to your wife.' He was a flirt until the very end."

"Oh yes, he's a great flirt," Zeta-Jones echoed to Entertainment Tonight.

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"He crosses our minds every day. But for me, during this time of, 'OK, we are all locked down, what do you do?' It's so easy to go into a procrastination vibe," she noted. "And Kirk, he went through so much from a helicopter crash to a stroke and then just age, being alone and what does he do with this time.

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"And what was so admirable about him was he was always involved with courage events, he wrote 11 books, he worked with his rabbi, he worked with his philanthropic endeavors and he always created something to do and he taught me that lesson," Zeta-Jones explained. "He always said to us, 'Write a book, do something else. What are you doing?' And he'd be working on something right now, I’m sure."

Fox News' Mariah Haas contributed to this report