Since wife Vanessa Minnillo gave birth to their son, Camden, last September, he's been relishing in all the highlights of fatherhood, including his first Father's Day and the milestone he's pretty sure took place during it.
"I'm convinced he said 'dada' for the first time on Father's Day. I have witnesses. It happened," he told MTV News. "The kid is smart. He saved it for the big moment. He's got a flair for the dramatic. He takes after his mom."
While Camden may have inherited Vanessa's "flair for the dramatic," together the parents are passing along their love for music to their 10-month-old. Earlier this year, Lachey recorded a lullaby album, A Father's Lullaby, which he released back in March in honor of his little bundle of joy.
"He gets the live version. Music's a big thing in our house. Both Vanessa and I are big music lovers. Singing to him is a big thing," he explained. "I wake him up every morning [and] sing to him. I put him down for naps [and] sing to him. She puts him down at night and sings to him. We all have our own special song that we share to him.
"There's one that I used to hum before he was even born and it's called 'Sleepy Eyes' and it's one on the record," he continued. "And that's the one I sing to him every night when I put him down [to sleep]. So at least in my mind, it's his favorite."
Lachey and Minnillo joined the celebrity parents club last fall and a slew of new A-listers took up membership in it last month, including Channing Tatum and wife Jenna Dewan-Tatum, as well as Lachey's former gal pal, Kim Kardashian and beau Kanye West. But, if they're looking for any advice, he's not the guy they should call on.
"The best advice I got, as far as getting advice, is don't give advice. Every parent is different. Every child is different and kind of the fun of the whole thing is figuring out what the heck works with your kid. You figure it out 'cause you have to," he said. "I think parenting is the most incredible experience I've ever been through. It'll change your life."