“Happy Birthday @gwenstefani!!!! I love you so much it’s actually stupid… And possibly illegal in the state of California,” he wrote.
The couple are no strangers to PDA on social media. In June, Stefani shared her own sweet message on Instagram for Shelton’s birthday, along with several Instagram Story videos of his birthday celebration and the duo kissing.
“Happy b day to my favorite human!!! Can’t believe your [sic] mine,” the “Hollaback Girl” singer captioned two throwback photos of Shelton in a Canadian tuxedo and cowboy hat. “#soooooolucky!!!! Gx #2019 #gemini #greatestguyiknow thank u shedd aquarium Chicago for an amazing unexpected b day tour!!!”
Shelton and Stefani reunited on The Voice in September after longtime judge Adam Levine decided to exit the NBC competition series ahead of season 17. Stefani gushed about working once more with her love during an interview on The Talk in June.
“It’s going to be fun and exciting. Blake’s my best friend. So, I get to hang out with him at work. Yeah. It’s going to be great,” Stefani dished at the time.
The 43-year-old country singer and the No Doubt frontwoman have been inseparable since they began dating in September 2015 during the ninth season of The Voice. Stefani revealed that she didn’t know Shelton existed before joining the series.
“I didn’t even know he existed before the show. I didn’t even know that he was a human being on this planet,” she told Andy Cohen on his SiriusXM Radio Andy show in September. “He’s so good at the show. I mean, he’s just so magical. Blake is literally a unicorn. Like, anywhere he goes, people are just attracted to him. He’s such an incredible talent.”
The “Cool” songstress was previously married to Bush guitarist Gavin Rossdale, with whom she shares three sons: Kingston, 13, Zuma, 11, and Apollo, 5. Shelton parted ways with his former wife, Miranda Lambert, in July 2015. (Lambert has since bounced back with NYPD officer Brendan McLoughlin, as the couple secretly married in January. Rossdale, meanwhile, was most recently linked to model Natalie Golba.)