Gwen Stefani celebrated her son Apollo's sixth birthday on Friday with a cute Instagram post co-starring her boyfriend, The Voice coach Blake Shelton. The country singer has become a major figure in the lives of Stefani's sons Apollo, Zuma, 11, and Kingston, 13. Their father, Gavin Rossdale, also shared a cute photo on Instagram to celebrate Apollo's birthday.
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On Friday, Stefani shared a selfie with Apollo, Shelton and a delicious-looking birthday cake with Oreos in it. "6 years ago GOD blessed us w this little angel... boy," Stefani wrote in the caption, along with the hashtags "Thank you God," "Happy birthday" and "Apollo."
Rossdale shared a gallery of photos with Apollo on Friday.
"My love turned 6 - endless magic endless joy endless nutella... Apollo we all love you so much," he wrote in the caption.
Shelton and Stefani have been dating since 2015. Sources previously told PEOPLE he has become a "strong male figure" to Stefani's sons while remaining respectful of Rossdale's role.
"He's so fun and has shown Gwen's kids another side of life filled with adventure," a friend told PEOPLE. "The boys have really grown immensely by spending time with Blake."
In September 2019, Stefani told Today Shelton is a "good dad" to her children, although Shelton does not have children of his own.
"He's been helping me out a lot, so I literally get to the point where I'm like, 'You gotta get home, I need help,'" Stefani said at the time. "It's hard. I got three boys."
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"I just never thought in my wildest dreams, on paper, a cowboy and a ska-like girl from Anaheim would be hanging out, but it works perfect and we're just having so much fun, and we just feel so blessed to be at this point in our lives," Stefani later said of her relationship with Shelton. "And, I don't know, it is awkward to talk about it, actually, a little bit."
Stefani and Shelton collaborated on the 2017 Christmas single "You Make It Feel Like Christmas." They also recorded "Nobody But You," a single on Shelton's 2019 greatest hits album Fully Loaded: God's Country, together.
"God's Country," the title song from his hits compilation, earned Shelton ACM Awards nominations for Single of the Year, Song of the year and Video of the Year. "Dive Bar," which features Garth Brooks, was nominated for Music Event of the Year.
Shelton recently joined Stefani on stage in Las Vegas to make a surprise appearance at her "Just a Girl" residency. They performed "Nobody But You" together, following a speech about the song before Shelton arrived.
"I was thinking about just the weirdness of my whole life and career," the former No Doubt singer said. "It doesn't feel like a career, it feels like a life. And then I was looking on iTunes this morning and I'm number one on the country chart, so I just thought that was like, kind of incredible."
Meanwhile, Shelton has returned for his 18th season as coach on The Voice. Kelly Clarkson and John Legend returned as well, with first-time Voice star Nick Jonas replacing Stefani. The show airs Mondays at 8 p.m. ET on NBC.
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