Jessica Biel has penned a heartwarming tribute to Justin Timberlake.

Justin Timberlake (c)  Instagram

Justin Timberlake (c) Instagram

The 38-year-old actress - who has five-year-old Silas and four-month-old Phineas with Justin - honoured her husband with a sweet message to celebrate his 40th birthday on Sunday (31.01.21).

Sharing a series of snaps on Instagram, she wrote: "There’s no one I have more fun with, have more laughs with, feel more deeply for, and have more history with. I honor you today, baby. And wish you the most creative and fulfilling year to date. Happy 40th, my love."

The couple began dating in 2007 before Justin popped the question in 2011 and they married the following year in Italy.

They recently welcomed their second child together with Justin confirming the news last month, saying: "He's awesome and so cute, and nobody's sleeping ... But we're thrilled. We're thrilled and couldn't be happier. Very grateful."

The 'Can't Stop the Feeling!' hitmaker tries not to hide his children out of the spotlight but is "conscious" about their privacy.

He shared: "I try to be conscious of making sure we can live a life where we're not weirdly private but we're conscious of making sure they can be kids for as long as possible. And not have the weight of somebody else treating them differently because of something that their parents do ...

"For guys like us, you know, the hope is that we just keep instilling in them that we got really fun jobs, but it's not who we are. Hopefully down the road, then that has more weight to it I guess."

What's more, Justin previously said he has "become a mess" since he became a father.

Asked what makes him cry, he said: "I'm a softie, man. Watching your son learn the smallest thing can bring you to that place, for sure. I have become a mess since I became a father."