Blake Shelton expressed disappointment that Luke Bryan did not wish him a happy birthday, joking that Bryan would only do so after seeing his tweet. Bryan later responded with a playful message excluding Shelton from birthday wishes. Despite the exchange, it seems to be a friendly banter between the two country stars. Shelton is currently on a break while Bryan is gearing up for a weekend of shows.
Source: https://tasteofcountry.com/luke-bryan-blake-sheltons-birthday-request/