Stephen Baldwin Spills on Seeing Hailey Bieber as a Mom, 'Plump Potato' Grandson Jack (Exclusive)

While speaking exclusively to TooFab ahead of his appearance on Special Forces: World's Toughest Test, the actor opened up about the couple's four-month-old baby.

"We're getting ready for Christmas with Baby Jack Blues," Baldwin exclusively told TooFab. "We're excited. And he's grown like a weed. Actually, he looks like a little plump potato. He's so cute. I can't stand it."

"I want to say so much," he said, before stopping himself.

The 58-year-old actor is already a grandfather to Iris, who was born in August 2020 to his daughter Alaia and her husband Andrew Aronow ... and, thanks to them, so he already has cute nickame for baby Jack to call him.

"Grampy. We're going with Grampy. But it's with a W. A lot of people don't know that," he told TooFab. So G-W-A-M-P-Y is Gwampy. So that's kind of the handle I've been going with. It was my granddaughter Iris, my first grandchild. It was the name she gave me."

The Biebers welcomed baby Jack in August this year; while they've teased him on social media, they have yet to share his face with their eager fans.

Baldwin took on the challenge of FOX's Special Forces: World's Toughest Test, telling TooFab the experience was "messed up" and that it would take a lot of money for him to do it again.

Initially, Baldwin joked he thought joining the cast could be a way to "work with Nicole Kidman."

"No, I wanted to do it because I thought, kind of stupidly, 'How hard could it be?' I really kind of thought, I've done some crazy stuff, I've raced motorcycles, I've raced cars, I jumped out of airplanes as a skydiver. And to do that on your own, you could do a tandem skydive, you could do kite surfing, you could do all these other aerial things. Skydiving is kind of the one where, you better know how to figure it out. But this was no way to figure it out," he recalled of his time on the show.

Baldwin was thrown into the deep end on the first day, revealing a moment that pushed him to the edge involving one of the Special Forces experts, Billy.

"It wasn't the way Billy treated me. It wasn't what he physically did. It's the words he used. If an instructor on Special Forces says, 'Get that smile off your face', and you don't, it's answered in a response by them with a physical reality," Baldwin said.

When we asked if he would ever do it again ...

"No," he quickly answered. "I would never do this again. I mean, if they paid me like $10 million, and they didn't pay me $10 million on this one, none of us got $10 million. But think about that, because I didn't even make close to a million dollars. It was that messed up. And I jump out of perfectly good airplanes. So when Billy went, 'Get that smile off your face, it's 10 million for the sequel, folks!"

Season 3 of Special Forces: World's Toughest Test premieres January 8 on Fox.