Season 14 Voice coach Alicia Keys turned 37 on Jan. 25, and to celebrate, her fellow coaches on the hit NBC reality show recorded a sweet message marking her special day and welcoming her back to the show.

Well, sweet and a little sour. "I just wanted to wish you a happy birthday," Blake Shelton began his tribute to the 15-time Grammy winner, who is returning to the show after leaving following Season 12. "I'm so glad you're here."

He then followed that up with this bomb: "I still stand by what I say -- you're the worst coach we've ever had on The Voice."

Aw, snap. Sounds like Shelton (who is the currently reigning coach, having won Season 13 with team member Chloe Kohanski) is still stinging from Keys' victory with Chris Blue back in Season 12.

Shelton, of course, took time to make sure everyone knew his words were all in the spirit of the game, and not to be taken seriously. "Even though you're my arch enemy on the show, you're one of my favorite people in the world," he said. "I love you."

Coaches Kelly Clarkson and Adam Levine added their own messages to the video, with Clarkson enthusing "I'm so excited for your birthday, that we should have some candles and cake and fun," and Levine being a tad sterner by warning, "I’ll see you in February, where I’ll beat you at The Voice!"

The Voice Season 14 premieres on NBC on Monday, Feb. 26.

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