The country crooner, who just turned 44 Thursday, is also Stefani’s best friend.
The “Make Me Like You” singer made that declaration on Instagram in honor of Shelton’s big day.
“Happy birthday @blakeshelton,” she wrote. “Thank u for being my best friend.”
She also added the hashtag “#luckyme,” along with a cake and party hat emoji.
While the message was brief, the photo that accompanied it also did the talking. In it, Shelton, decked out in a Hawaiian shirt, flashes a big grin at the camera as his 50-year-old gal pal plants a kiss on his cheek.
The pic was good enough for a second post over on Twitter, though for that one, Stefani gave her bestie another title: “my boo.”
But Shelton’s birthday isn’t the only special occasion they've celebrated lately.
At the end of April, their duet “Nobody But You” hit the top spot on the Billboard Country Airplay list, marking the first time on that chart for Stefani.
Then, by the end of May, they had something else to cheer about when Team Shelton singer Todd Tilghman won season 18 of “The Voice,” making the show’s founding coach a seven-time champ himself.
And just this week, NBC announced that Shelton will get some stiff competition on the show next season, because Stefani is returning to her red swivel chair as a coach once again.
Stefani first joined the talent competition as a coach in season seven. She also served alongside Shelton in seasons nine, 12 and 17, too, in addition to taking on an advisor role in seasons eight and 10.
And just like in the birthday message she shared for Shelton Thursday, the last time she returned to the show, she raved about her “best friend Blakey.”
Of course, it’s never a surprise to hear the singer share such kind words about the man she’s been dating since 2015. After all, last year, she told TODAY that he was “the most lovable human being I’ve ever met.”