Gwen Stefani & Blake Shelton Celebrate Her Son Zuma's 13th Birthday With Heartfelt Message of Love

The newlyweds commemorated Zuma's milestone b-day.

Gwen Stefani's son Zuma is officially a teenager! The songstress and new husband Blake Shelton celebrated her little boy's milestone birthday together.

Stefani, 51, commemorated Zuma's big day with a series of snapshots posted to her Instagram page and her Story.

The multitude of posts included quite a few photos of Zuma as a small child, as well as a snapshot of herself, Shelton, and all three of her kids together for a smiling family photo.

"Happy Birthday!" Stefani added in colorful animated text below the group shot -- which also featured sons Kingston, 15, and Apollo, 7, whom she shares with ex-husband Gavin Rossdale.

Gwen Stefani/Instagram

She also shared a pair of pics showing how grown-up and mature Zuma is, starting with a baby photo, and then a contemporary snapshot of her new teen.

"Happy 13th b day to my Zuma baby 👶🏻 we love u so much!!" the proud mom wrote.

Stefani shared one additional throw-back photo of Zuma as a toddler at one of his early birthdays, swinging a small bat at a Spider-Man piñata.

She captioned the photo simply, "Babies grow up."

Gwen Stefani/Instagram

The group photo Stefani shared of Shelton and her kids mirrors a photo she posted from their wedding back in July.

The "Hollaback Girl" singer shared a precious photo of her and Shelton posing with her three kids on their special day at Shelton's Oklahoma ranch.

Check out the video below to hear more.