Hosts Carissa Culiner and Morgan Stewart -- the latter of whom is currently expecting her first child -- gushed as the six-month-old joined Nikki and Brie on the screen.
"He's so cute. His eyes are just stunners!" Carissa said of Matteo's baby blues, which he appeared to inherit from his dad, "Dancing with the Stars" pro Artem Chigvintsev.
As Nikki and Brie went on to play a game of "Trash Talk," a well-behaved Matteo sat on his mama's lap, at times staring right into the camera and showing off his adorable smile. And it was the cutest thing ever!
Meanwhile, earlier in the interview, the Bella twins teased Thursday's new episode of "Total Bellas," which will show the moments the former WWE stars each welcomed their baby boys.
Both sisters gave birth two days apart: Nikki gave birth to Matteo on July 31, while Brie and her husband Daniel Bryan, welcomed Buddy, on August 1. (Brie also shares 3-year-old daughter, Birdie, with Bryan.)
Brie revealed she and Nikki have watched the birthing footage "three times" so far and each time was emotional.
"We've cried every time," Brie said. "We just love it. And I think the neat thing is, you see Nikki have a vaginal birth and go through her thing and then I have a C-section. It is two completely different births within 22 hours. And It was just really special."
"I loved watching my sister in labor," Brie continued. "I was like, 'Oh my gosh, to see you like that is so weird."
Nikki said it was a little shocking to watch herself give birth as well.
"It's all of me there," she quipped. "This Thursday, you're going to see it all. I was even, like, 'Whoa, there I am.'"
Fans will also get to see Brie and Bryan's first reaction to learning the gender of their child.
Meanwhile, Nikki -- who got engaged to Artem last February -- also gave an update on her and Artem's wedding plans, revealing that the couple is shooting for November.
"My goal would be Thanksgiving 2021. I just want it to be in a time where we don't have to social distances or wear masks. It's so weird because ... do we start planning? Do we not? I don't know," Nikki said, adding that since Artem is a dancer she wants to "bump and grind" on her wedding night.
"Fall will be so pretty," Nikki continued. "I'm praying and hoping that we can start planning in a month or two knowing that by fall we will be opened up."
"Total Bellas" airs Thursday nights at 9 p.m. ET on E!.