The “Mirrors” singer, 34, called her his “best friend and favorite collaborator.”
He also made a reference to the upcoming birth of the couple’s first child.
“I can’t wait to see our greatest creation yet,” he said. “Daddy’s heading home right now to innovate and learn how to change a poopy diaper and get my swaddle on!”
Biel is expected to give birth very soon, although her exact due date hasn’t been announced yet.
The actress, who recently wrapped up filming for “The Devil and the Deep Blue Sea”, was recently spotted out and about in southern California, and even attended a friend’s birthday party at a roller rink in Glendale on Friday.
The couple has been incredibly private about Biel’s pregnancy, but Timberlake made the official pregnancy announcement in January on his 34th birthday.