For her part, the actress commemorated the day with a sweet photo of the foursome hugging.

"To the world, you are a dad," she wrote.

"But to your family, you are the world.

I don't know who said that, but whomever it was, they bodied that s--t. We love you baby.

So yes, it's safe to say the couple, who wed in 2012, can't stop the feeling...of happiness.

Jessica Biel & Justin Timberlake's RARE Family Photo