The 75-year-old actor and 50-year-old actress sent love to Kirk Douglas, Michael Douglas' father, on the actor's birthday Monday.
Michael Douglas shared a photo on Instagram of himself giving Kirk Douglas a kiss on the head. He called his dad, an actor known for The Bad and the Beautiful, Lust for Life and Spartacus, a "living legend" in the caption.
"Happy birthday Dad! You are a living legend and your entire family sends you all the love in their hearts! #KirkDouglas #103," Michael Douglas wrote.
Zeta-Jones posted a picture on her own account of Kirk Douglas sitting on her knee.
"This guy on my knee, is 103!!!!! Happy Birthday Pappy!!! I love you with all my heart," she captioned the post.
"Okay, so he was 100. Big birthday, big birthday. The trouble is, when you're 100, you don't really want a big birthday," Michael Douglas said of his dad. "I threw a big party for him, it was great."
"101. You know, 'Okay, let's have a nice party.' ... 102 ..." the actor added. "So he's begging me, he's got tears down his eyes. 'Let's just have dinner, the family together. Bring the kids.'"
"He's incredible. He doesn't get around a whole lot but his mind's all there, so I got him an iPad and I got him FaceTime," Michael Douglas said. "Loves it. It's fantastic."