• Will Smith opened up about the "terrifying" birth of his first son Trey during An Evening with Will Smith at the Grammy Museum in Los Angeles on Thursday, Oct. 3

• "It's crazy, but you're like, I cannot tell you what it was like bringing that child home on that first night and realizing that he was my responsibility," he said, becoming tearful.

• Smith added that he wrote his 1997 track “Just the Two of Us,” around the time of Trey's birth

Will Smith is getting emotional as he reflects on the “terrifying” moment he became a parent for the first time.

During a wide-ranging conversation as part of An Evening with Will Smith at the Grammy Museum in Los Angeles on Thursday, Oct. 3, the Oscar-winning actor and rapper, 56, became tearful as he shared the story of his son Willard Carroll “Trey” Smith III's birth in November 1992.

Ahead of performing his 1997 track “Just the Two of Us,” Smith told the audience that he had written the song during “probably one of the most terrifying times of my life.”

“It's when my son... Trey was born," he explained, adding that his eldest child, 31, — whom he shares with his first wife Sheree Zampino —  was actually in the audience at the event.

Smith went on to tell the audience that Trey was born during the second season of his hit '90s TV show The Fresh Prince of Bel-Air, when the actor was just 24.

"It's crazy, but you're like, I cannot tell you what it was like bringing that child home on that first night and realizing that he was my responsibility," he said, becoming tearful.

"He's cool now, thank God – he's going to be 32 this year," Smith — who also shares son  Jaden, 26, and daughter Willow, 23, with wife Jada Pinkett Smith, 53, — added.

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Trey Smith and his dad Will Smith

He went on to tell the audience that "parenting was one of the first things, the first real things in my life that really shook me to my core,"

"I remember that first night," Smith said, becoming tearful. "I can't even talk about it. Because I had talked so crazy about my father and all the stuff my father didn't do. And then I was like, 'Oh no, it is my turn now.' And I just fell down on my knees and I made one of the most hardcore promises ever made to a human being. That I was going to do everything I could do to be a good daddy to you."

Will wiped away his tears with a towel before sharing that he wrote "Just the Two of Us" that night and performing the track for the guests at the Grammy Museum.

Joseph Del Valle/NBCU Photo Bank

Will Smith and his son Trey on the set of 'The Fresh Prince of Bel-Air'

Ahead of his rendition of the song, Smith also recalled that Trey had arrived when he'd "just bought a picture-in-picture television," and compared the guidance he got for the TV to becoming a parent for the first time.

"His mother's water broke, Sheree's water broke and I had just opened my TV. I was trying to set my TV up and there was a thousand-page manual for my television. It was a thousand pages. It was that thick and it was multiple languages and I needed a thousand pages of information to get this TV set up."

"I remember I brought him home and put him in the bassinet," he said, adding that "Cedas-Sinai sent me home with a baby and not even a pamphlet."

Ron Galella, Ltd./Ron Galella Collection via Getty

Will Smith and son Trey Smith attend the 1997 "Men in Black" Hollywood premiere

Smith has previously discussed the connection between the song and Trey, including in his 31st birthday tribute to his son on Instagram in November 2023.

In the clip he posted, which seemed to be video footage filmed of himself creating his audiobook for his 2021 memoir, Will, the actor discussed the day Trey was born ahead of reciting lyrics from "Just the Two of Us."

After sharing some of the lyrics, which he said described the "public depiction of Trey's birth and my introduction to fatherhood," in a voiceover, Smith explained that he had been "overwhelmed with the immensity" of the responsibility ahead that came with being a parent, and revealed that he prayed to God on his knees to him be "a good daddy."

Meanwhile, the Oct. 3 event also saw the Oscar-winning actor and rapper perform new songs, as well as hits from “Summertime” to “Getting Jiggy Wit It,” “Miami,” and the lyrics to the theme song from The Fresh Prince of Bel Air, while his mom Caroline Bright, 87, was also in attendance.