The 35-year-old actress also dished on Timberlake's upcoming Super Bowl halftime show, and son Silas entering the 'terrible twos.'
After five years of marriage, Jessica Biel and Justin Timberlake's relationship couldn't be stronger.
ET's Nischelle Turner caught up with Biel at the exclusive preview of Au Fudge CAMP in West Hollywood, California, on Monday, where she revealed how she first knew Timberlake was the one.
"We had been dating for a little bit... There was just a moment when I called a girlfriend and I said, 'I'm going to marry this guy,'" the 35-year-old actress shared. "I don't necessarily know why, but I think a lot of people feel that way. It's not a tangible moment where you're like, 'This is it,' it just is, somehow."
Part of the reason why Biel and Timberlake work so well together is because they support each other unconditionally. The actress will be her husband's No. 1 supporter when he takes the stage to play the Super Bowl halftime show in February.
"It's going to be good," she gushed. "I guess I could be a little bit biased, but I think he puts on the best show of anybody."
"I'm just excited for him to have a really incredible place to perform and play some great stuff," she added.
And Timberlake, of course, supports his wife as she extends her family friend's L.A. restaurant, Au Fudge, to include a kid's CAMP (Center for Art, Music and Play), set to open in mid-November.
"It's a place where we want a kid's imagination and a kid's ability to sort of drive the experience," Biel said of the camp, formed with her partners, interior designer and stylist Estee Stanley, producer and author Kimberly Muller, CEO of Barry's Bootcamp, Joey Gonzalez, owner of Terrace Tower, Australia Monica Saunders-Weinberg and CEO of Greenleaf Gourmet Chopshop restaurants, Jonathan Rollo.
"You can just drop in here if you want to, and sit here and watch your kid play, but we really want it to be imagination-based, creative-based," Biel continued. "We definitely have a curriculum that we are setting up with the full range of classes."
"For kids two and under, they always have to be accompanied by a parent, but we are offering drop off for the majority of our classes," she continued. "We even have a play time."
The CAMP will definitely be a good place for Biel's son, Silas, whom she says is "in the midst of the terrible twos."
"There's a lot of 'No' going on in my house... It can be tough," she confessed. "We [need more] wine, friends, more places like this, where you can just sit back and let them go crazy, because they just need to go crazy for a while."
But first -- how will she, Silas and Timberlake top their epic Trolls Halloween costumes from last year?
"We are going to be Woody and Buzz and Jessie from Toy Story," she revealed. "If you're a cool parent, you're going to dress up."
See more on the adorable family in the video below.