In the clip posted to Instagram, Shelton starts to promote Bryan's new album, What Makes You Country, but soon takes a jab at his friend by says he "looks inbred."
"I just wanted to take a minute and tell you my buddy Luke Bryan has a new album that came out, and it's called What Makes You Country," Shelton said. "And it got me thinking, if he's saying that — 'what makes you country' — I start to thinking, 'What makes Luke country?'. And really, the only thing I can come up with is, he looks inbred."
Bryan hasn't commented on the diss, but he presumably won't mind due to its humorous intention.
This isn't the first time Shelton has made a joke at Bryan's expense. The "I'll Name the Dogs" singer has notably poked fun at Bryan during a couple of Academy of Country Music Awards ceremonies.