Jessica Biel can't stop feeling like time is flying.

For the Candy star and husband Justin Timberlake, nothing exemplifies this more than seeing their eldest son Silas, 9, rapidly change right before their eyes.

"He went from this little guy to this kind of more grown-up kid," she said on the May 21 episode of SiriusXM's Let's Talk Off Camera with Kelly Ripa podcast, "and even Justin and I are like, ‘Wow, this kid is looking different all of a sudden.'"

As Silas reaches this stage, Jessica shared insight into the conversations about puberty they've started having.

"We talk a lot about his body's changing a lot and he's experiencing that," the 42-year-old continued. "He's experiencing growing pains. He has a hard time sleeping. He'll be waking up in the middle of the night. His legs hurt. His back hurts. He's, you know, he looks different, right?"

Jessica emphasized that she and Justin, 43, have made a point to discuss these changes, adding, "We're talking about deodorant. We're talking about hormones in our bodies and why we smell a different way, and so we're into it and we're on the precipice of all the big conversations I think."

Overall, the 7th Heaven alum—who also shares 4-year-old son Phineas with Justin—is just amazed by what "a cool person" her eldest is.

In addition to making sure Silas feels a sense of normalcy about puberty, Jessica and the *NSYNC alum are committed to their boys growing up out of the spotlight. This is why they chose to leave cities like Los Angeles and New York and instead raise their kids in Montana.

"It's just trying to create some normalcy for these kids," she explained. "We wanna share our family with our loved ones and friends."

Jessica added, "I don't wanna expose them in a way until they have an ability to make that decision for themself."

And other big plus about Montana? Very little paparazzi.

"You get hammered in the East Coast, you kinda get hammered on the West Coast," she said. "That's why we don't really live there anymore."

For more of Jessica and Justin's adorable family, keep reading.

Justin Timberlake and Jessica Biel's sons Silas and Phineas rocked the singer's Forget Tomorrow World Tour merch when he kicked off the concert series in April 2024.

Jessica hugged the couple's youngest son Phineas, as seen in this video Justin shared on the actress' 42nd birthday in March 2024.

Justin shared this pic on Jessica's 42nd birthday in March 2024.

Justin also shared this snap on Jessica's 42nd birthday in March 2024.

Jessica posted a sweet family snapshot as part of her Instagram tribute to Justin on Father's Day 2022. 

Justin celebrated Father's Day 2022 by sharing a photo of his "two favorite melodies," sons Silas and Phineas, playing piano together. 

Jessica shared this sweet pic of herself with sons on her 40th birthday.

This was Silas and Phin's birthday banner for Jessica.

Justin and Jessica enjoyed cake on her 40th birthday.

"Thankful for my guys," she captioned heartwarming holiday snap. "Merry Christmas everybody!!"

Jessica celebrated her "little man" on his big day back in April 2020. Happy birthday, Silas! 

The Sinner actress marked her birthday on March 3, 2020 with a special cake and her one and only. On Instagram she wrote, "Celebrating my birthday in style... and by that I mean, in pajamas. I made Justin PROMISE not to sing Happy Birthday to me, so he improvised. Sorry you can't hear it, but I'm still laughing. Thank you, you wonderful human, for really listening to me, and for throwing my kinda party. And thank YOU ALL for the birthday wishes. Feeling the love." 

On Valentine's Day 2020, Jessica shared a sweet picture of Justin and their son Silas on Instagram. She captioned it, "My valentines. Love you guys to the moon."

Jessica and Justin looked madly in love at her birthday party in March 2019.

Justin, Jessica and son Silas celebrated Fourth of July 2019.

The trio enjoyed some time at the beach to mark the holiday.

When it comes to Halloween night, Justin and Jessica always go all out. Anyone remember their Toy Story looks from 2017? 

"Happy Halloween from Poppy, Branch and lil Branch. We be Trollin'..." Jessica wrote on Instagram after Halloween 2016. 

"If that pic doesn't say ‘City Of Love' then I'm out..." Justin shared with his social media followers in July 2018. We can't help but agree. 

"They got candy? LEGO!" Justin shared with his Instagram followers on Halloween 2018. 

"To my husband who I watch with awe everyday as he guides and teaches, encourages and supports, and above all, LOVES the sh$t, out of his own young man," Jessica wrote on Instagram. "Happy Father's Day to all the dads out there. We can't do this parenting thing without you."

The famous trio dressed up as Batman, Robin and Harley Quinn for Halloween 2018. "This Halloween was one hell of a block party!" she shared on Instagram. "Happy Halloween from our LEGO family to yours."