Justin Timberlake and Jessica Biel have two sons, Silas and Phineas

Mom of two Jessica Biel is enjoying Mother's Day!

The Cruel Summer producer, 39, shares two sons — Phineas and Silas — with husband Justin Timberlake, who shared a heartfelt tribute to her for the holiday.

"Moms are the strongest people on the planet. I am constantly in awe of the mothers in my life. Jess - you're the heart of this family. Your boys look up to you and love you unconditionally. And so do I," he wrote alongside a photo of the pair walking side-by-side.

The singer also shared a kind message to his mother Lynn.

"And mom - your strength and support have taught me everything I know about being a parent. I'm so grateful your guidance and I hope I make you proud," he wrote. "Happy Mother's Day to all the BADASS Mom's out there! I bow down to you all!🙌🏻"

Justin Timberlake and Jessica Biel pose for portrait at the Premiere of USA Network's "The Sinner" Season 3 on February 03, 2020 in West Hollywood, California
Justin Timberlake and Jessica Biel
| Credit: Rodin Eckenroth/Getty

In April, Biel shared on The Ellen DeGeneres Show that her two boys can't get enough of one another. Asked whether they get along, Biel explained that Phineas, whom the couple welcomed last summer, and Silas, 6, "both think the other one is hilarious."

"Silas, he is the performer, he wants to make the jokes and he wants the whole attention on him, so Phin only has eyes for him," The Sinner actress said.

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Jessica Biel and Justin Timberlake
Jessica Biel and Justin Timberlake with son Silas
| Credit: Justin Timberlake/Instagram

"Everything Silas does is hilarious and anything Phin does is hilarious, so they just laugh at each other all day long," she continued. "It's so cute."

Speaking about being a mom of two, Biel said it's been a "wild, crazy, fun ride" thus far. "A very wise friend of mine said, 'One is a lot, and two is a thousand.' And I said 'Oh my god, you're right,' " she said. "That's exactly how it feels. You're just man-on-man defense, one person's over here and the other person's over here."

In January, Timberlake confirmed he and Biel welcomed a second child during an episode of The Ellen DeGeneres Show. "He's awesome and so cute," Timberlake said of the couple's new addition at the time. "Nobody's sleeping, but we're thrilled. We're thrilled and couldn't be happier. Very grateful."