Gwen Stefani, Blake Shelton Share Sweet Family Photo On Her Son Zuma's 13th Birthday

Gwen Stefani's son, Zuma, turned 13 years old, and the singer and her new husband Blake Shelton celebrated her little boy's milestone birthday together.

On Saturday, Stefani, 51, shared on her Instagram page and her Story a series of posts to mark Zuma Nesta Rock Rossdale's birthday.

"Happy 13th [birthday] to my Zuma baby. We love [you] so much!!" she captioned photos of Zuma as a baby and as a teen.

She also posted on her Instagram Story a family photo with Shelton and her three sons Kingston, 15, Apollo, 7, and Zuma — whom she shares with ex-husband Gavin Rossdale.

In the picture, a smiling Zuma is seated between his mom and older brother wearing a printed white T-shirt, black cap and glasses. Behind the three are Shelton and Apollo, both of whom flashed huge smiles at the camera.

"Happy Birthday!" Stefani added in colorful animated text below the group shot

In another post on her Story, the "Hollaback Girl" singer shared a video of Zuma whacking a Spider-Man piñata when he was a toddler. "Babies grow up," she wrote in the caption.

Rossdale also marked his son's birthday on social media, posting a sweet tribute for him on Instagram. He shared a clip of Zuma practicing his boxing skills.

"My sweetest boy turns 13," Rossdale wrote in the caption. "You, young man are the most precious part of my life. Thanks for all the light you bring. Also head of security position is open."

All three of Stefani's sons are reportedly close to Shelton. In June, the No Doubt lead vocalist shared a series of pictures of Shelton with her children for Father's Day.

"Happy Father's Day to the most generous, patient, loving [and] funny guy I know. We love [you] so much @blakeshelton," she wrote in the caption.

Stefani and the country singer started dating in November 2015 following her divorce from the Bush lead singer and tied the knot in July in an intimate ceremony in his Oklahoma ranch.

An unnamed source previously told Entertainment Tonight that Stefani's kids were part of Shelton's proposal plans "every step of the way."

"Blake is very close to Gwen's boys," the insider told ET. "They talked it through and Blake made sure they were part of the excitement! Blake had a custom-made engagement ring. He knows the designer and has used them in the past to make bracelets for Gwen."