AceShowbiz - Justin Timberlake penned a touching Father's Day message to his boys, Silas, 9, and Phineas, 3, whom he shares with wife Jessica Biel. Celebrating the special day on Instagram, the "Mirrors" singer shared photos of his sons and expressed his love and gratitude.

In the caption, Timberlake wrote, "I learn more about myself every day because you both chose me to be your Daddy. I will always be there for you through your peaks and valleys... to lift you up and show you how high you can take this life and to pick you up when you fall."

He continued, "And, of course, to flood you with insufferable Dad-jokes all along the way. I love you both so much. Thank you for giving me my biggest purpose."

The singer revealed his Father's Day plans, which included watching the final round of the US Open with his family. He also shared an Instagram Reel where he expressed his exhaustion but wished all the dads out there a Happy Father's Day.

Earlier this month, Biel spoke to PEOPLE about her debut children's book, "A Kids Book About Periods," which aims to destigmatize menstruation for young readers. She shared that she has been teaching her son Silas about the topic.

"My son and I read half of the book for the first time this morning, it was really cool to see him listening," Biel said. "He would read a page and I would say, 'Okay, so this is what's happening.' And I said, 'Okay, this is the period. This happens to me every month. And it'll happen to people in school.' "

Timberlake has previously expressed his joy as a father, saying that his sons "run our house." He also appeared on "The Tonight Show Starring Jimmy Fallon," where he described them as "both so cute."