The teen celebrated his special day on Aug. 21.
Zuma Rossdale turned 15 on Aug. 21, with his mom posting a loving tribute on Instagram.
"Happy 15th birthday Zuma !!! we love u more than anything," Stefani wrote, sharing a video slideshow including snapshots of Zuma over the years. In one of the pics, Zuma poses happily with step-dad Blake Shelton as he shows off some homemade artwork. The cute clip is set to Zach Bryan's 2022 hit, "Something in the Orange." In nearly all the pics, the teen looks like the spitting image of his pop star mother.
In addition to Zuma, Stefani shares 17-year-old Kingston and 9-year-old Apollo with her ex-husband, Gavin Rossdale.
Earlier this year, as 47-year-old Shelton wrapped up his final season as a coach on NBC's The Voice, the country superstar told ET he was looking forward to spending more time with Stefani and the boys.
"I want to finally have the opportunity to say yes to more stuff in my personal life," he shared, "and not say, 'Let me check,' or just flat-out no."
Meanwhile, 57-year-old Rossdale recently issued a rare comment on his experience with co-parenting alongside his ex.
"I think you can go one of two ways," he said in an interview on the Not So Hollywood podcast. "You can either do everything together and really co-parent, and see how that goes, or you can just parent. And I think we just parent ... We just parent."
He continued, "We're really different people ... I don't think there's much similarity in the way we bring them up, but I think that gives them an incredible perspective to then choose which pieces of those two lives they'd like to inherit and move on with and which part of themselves come out of the whole process."
The former couple was married from 2006 to 2014.
Stefani, 53, went on to marry Shelton in 2021 and the pair celebrated their second anniversary last month. They've also been working together in the studio as of late, rerecording the iconic 1984 ballad "Love Is Alive" for an upcoming tribute album for The Judds.
Stefani's vocals take center stage on the reimagined track, with Shelton providing the harmony. The enduring love song is featured as the first single off A Tribute to the Judds, a compilation album to be released Oct. 27 on BMG in honor of The Judds' 40th anniversary.