"This is absolutely unbelievable," Shelton began after hugging Stefani. "First of all, thank you Gwen Stefani."
"Thank you!" Stefani responded. "My gosh. I can't believe it. Country music! What is happening to my life?"
After getting their bearings a bit, Shelton revealed that he didn't think he and his girlfriend were going to take home the trophy.
"I told Gwen, when I saw who the other nominees were in our category, literally it was like, 'That would've been cool, but I don't know what our chances of beating Justin Bieber are,'" he recalled. "But here we are! So thank you so much... Fan-voted awards are, to me, the only stand-up award shows left in our industry it feels like sometimes. You guys are the ones who buy the records, you come to the shows, and you vote on these things. So we love you so much."
"I love you so much," he added, turning to Stefani, who reciprocated the love to her beau.
"This means the world to us, more than you can probably imagine," Shelton added, before joking, "This is a crazy pairing in lots of different ways, but it's working!"
The couple beat out Carly Pearce and Lee Brice's "I Hope You're Happy Now,” Dan + Shay and Justin Bieber's “10,000 Hours," Kane Brown and Nelly's “Cool Again," Marshmello and Kane Brown's “One Thing Right” and Thomas Rhett and Jon Pardi's “Beer Can't Fix."
Stefani and Shelton's Sophie Muller-directed video debuted in January. A month before the video dropped, the country crooner told ET how the song was the perfect duet for them.
"Gwen was crying when we even just talked about singing it together at all," Shelton told ET in December. "It just seemed to fit perfectly with our story, and, musically, I think it walks the line of what I can do and what she can do. Everything just kind of aligned and came together, and it's one of those once-in-a-lifetime moments."
The two have also worked together on "Go Ahead and Break My Heart," You Make It Feel Like Christmas" and, their latest, "Happy Anywhere."