The baby boy, whose name has not yet been announced, came into the world on Tuesday in Los Angeles. It's the second son for the happy couple, who are already the parents of daughter Ella, four, and two-year-old Michael.
The handsome 37-year-old, whose older brother, Donnie, is currently enjoying success with reformed band New Kids On The Block, is clearly in his element in his role as dad in his busy household, which he describes as "hectic at times, but a lot of fun".
And the latest member of the family may not be the last, revealed the Oscar-nominated star. "When the kids are good, we want eight or nine," he said before quipping: "When they're bad, we want to stop at three."