Nick Lachey serenaded his daughter in sweet video: 'Daddy's girl forever'

Lachey got his little girl's heart fluttering when he belted out a 98 Degrees song.

Nick Lachey sang a special love song to his No. 1 fan on Friday.

The singer's wife, Vanessa Lachey, took to Instagram to share a video of him serenading the couple's 3-year-old daughter, Brooklyn with the 98 Degrees ballad "I Do (Cherish You)."

In the black-and-white video, Nick sings to tiny Brooklyn as she sits on a stool beside him, clutching his arm adoringly.

The adorable little girl smiles and kicks her legs happily as her dad sways from side to side singing, "All I am, all I'll be, everything in this world, all that I'll ever need is in your eyes, shining at me."

Vanessa captioned the precious clip "Daddy's Girl Forever."

Nick and Vanessa Lachey

The couple, who tied the knot in 2011, are also parents to two boys, Camden, 6, and Phoenix, 1.

In honor of Father's Day this past June, Nick shared a photo of himself with all three of the couple's kids. In the caption, he gushed about how much fatherhood has changed his life.

"There is nothing more impactful, life changing, rewarding, and truly special than a child in your life," he wrote."I am blessed to have 3 beautiful little people and every day I spend with them is one step closer to heaven."

"Camden, Brooklyn, and Phoenix," he added, "there is no greater honor and privilege than to wake up every day as your Daddy."