Blake Shelton Jokes Garth Brooks Is Bullying Him About Being 'Mr. Stefani' (Exclusive)

The country crooners open up to ET after their debut live performance of their new song, 'Dive Bar.'

Garth Brooks is having fun giving fellow country singer Blake Shelton a hard time.

The bestselling musicians teamed up over the weekend to deliver the debut live performance of their recently released collaboration, "Dive Bar." Shelton made an appearance during Brooks' concert at Albertsons Stadium at Boise State University in Idaho on Friday and fans freaked out about the exciting live team-up.

ET was with the duo after the performance and Shelton revealed how Brooks welcomed him with some playful ribbing over the Voice coach's adorable, high profile romance with Gwen Stefani.

"I got a text from my man here earlier that said, 'Hey, man, we got your dressing room set up for you,'" Shelton recalled. "And he sent me a picture and it was a paper that said 'Mr. Stefani' on it."

The singer jokingly added that Brooks has been "bullying" him a "little bit," and there's really nothing he can do to get back at him.

"It sucks because Garth is kind of off-limits," Shelton said with a laugh. "You can't mess with him because he's like the godfather of country music."

Brooks, meanwhile, denied the possibility, joking, "You ever think this big of a boy has been bullied, ever?"

While Shelton might have gotten messed with a little, it wasn't anything he didn't take in stride -- even though "Mr. Stefani" wasn't able to debut the single in front of his ladylove. While Brooks' wife, Trisha Yearwood, was in attendance at the stadium stop, Stefani couldn't make it, despite wanting to.

"I wish, and she wishes too, [but] she has her Vegas residency going right now, so she's got a performance," Shelton explained. However, he said he wasn't worried about Stefani getting a chance to check it out, adding. "I think in seconds of looking on Twitter or Instagram, she's going to get all of it she can imagine, it'll be all over the place."

"Blake's worrying about throwing up. I'm just thinking, 'Be as tall as you can and suck it in!'" Brooks added with a laugh.

The duo's high-profile duet -- which was also recorded as part of the music video for the single -- came during a stop on Brooks' Stadium Tour, which kicked off March 9 and continues through Aug. 10, with two back-to-back shows at the Mosaic Stadium in Saskatchewan.

Brooks is also promoting his "Dive Bar" duet with Shelton -- which will be featured on Brooks' upcoming album, Fun, with a seven-stop Dive Bar Tour, sponsored by Seagrams 7, which features the iconic country crooner performing in local bars around the country.