In fact, the brothers, who each have two young children, have their hands full with their little ones. And according to the Succession actor, that's part of the reason he has yet to meet Macaulay and Brenda Song's newborn son.
"Well, the cousins live in Los Angeles, we live in New York," Kieran, 40, told Access Hollywood at Succession's season four premiere March 20. "I have a 1-year-old and a 3-year-old and as busy as I am there is no getting on a plane and going."
He added, "I haven't met number two yet and they haven't met my number two yet either because we just haven't been able to figure that out."
And while his work as Roman Roy on the HBO series has taken him all over the world—including Italy and the United Kingdom—during his downtime, he can usually be found "at home with my wife and kids."
In the big apple, Kieran and his wife Jazz Charton—whom he tied the knot with in 2013—are parents to daughter Kinsey, 3 and 19-month-old son Wilder. And back in 2021, the Father of the Bride actor revealed that he and Jazz didn't settle on a name for their littlest until two months after his birth.
"We found it at the hospital the day that he was born, and we thought, ‘That's great. But instead of pulling the trigger on it, let's torture ourselves about it for seven weeks, disagreeing with names before we come around to the name that we picked,'" Kieran explained on the Ellen DeGeneres Show. "We didn't know if we were having a boy or a girl, and we had a long list of names … at the hospital."
Meanwhile, across the country, the Home Alone star and the Suite Life of Zach and Cody actress—who also share 23-month-old son Dakota—have kept their family life largely out of the public eye.
E! News confirmed March 17 that the couple quietly welcomed their second child, a baby boy.
Last year Brenda—who got engaged to Macaulay, 42, in January 2022 after more than four years together—shared a glimpse into her motherhood journey.
"My fiancé and I are very hands-on," the Disney Channel alum, 34, told The Cut in January 2022. "We don't have a nanny, but my mom has been here with us since my son was born. When I was working, my mom would bring my son to set so I could breastfeed and see him during the day. People tell you a lot about labor and pregnancy, but not about the fourth trimester."
As for how she and Macaulay balance their relationship amid life with a newborn? For Brenda, communication is the key.
"I think when you and your partner have kids, especially the first few months, you don't have the patience to be polite with each other," she noted. "Being communicative when you need help is so important. Instead of having set duties, we just feel each other out. I'll be putting my son down and my partner is like, 'Let me feed the animals and get dinner ready.' "