Colin Jost Opens Up About Son Cosmo's Relationship with Scarlett Johansson's Daughter Rose: She's a 'Loving Sister'

Colin Jost's son Cosmo is spending some quality time with his older sister.

The Saturday Night Live star, 42, spoke with E! News ahead of the premiere of his new comedy special Colin Jost & Michael Che Present: New York After Dark, opening up about his family life at home with wife Scarlett Johansson, 39.

The famous couple is parents to 3-year-old son Cosmo, while Johansson shares daughter Rose, 10, with ex-husband Romain Dauriac.

"The two of them spent a lot of time together this summer, which was nice for them," Jost says of Cosmo and Rose. "She's a very nice, loving sister."

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"Normally she's got her own life," the proud dad jokes, "but this time she was forced to stay with him for a lot of time, and they got along really well."

Jost went on to say that Rose was even there for one of his son's biggest moments of the summer.

"He drank some milk and then said, 'Some things in life you just have to savor,' " Jost teases. "Which I was thought was nice."

"He is funny. He's sort of shy sometimes, but he's a gregarious little guy. He's fun," adds the comedian.

This past July, Jost opened up to The New York Times about his relationship with Johansson's daughter Rose, sharing that he was enamored with the Avengers actress after seeing her as a parent. "I think part of the reason I fell in love with her is she’s a great mom,” the comedian revealed.

"I’ve known Rose, my stepdaughter, since she was 2," Jost told the outlet. "It’s weird. You get to actually preview someone as a mom.”

In April, Jost appeared on an episode of the iHeartPodcast Table for Two with Bruce Bozzi, sharing some of his favorite activities to do with his son Cosmo.

"One thing that's really important with [Cosmo] is I take him swimming a lot whenever I can — like pool or ocean," Jost shared.

"He's only 2 and he's a pretty good swimmer actually, like he's almost independent swimming, which is kinda crazy. He's a smart guy, too, such a fun kid."

"I didn't always love the competitive part of swimming, but I did love being in a pool and I'm very happy around water all the time. And that's something I'd like to share with him in different ways."