 " Big Brother " is the fifteenth episode and spring premiere of the third season of the American musical television series Glee , and the fifty @-@ ninth overall . Written by Michael Hitchcock and directed by Eric Stoltz , the episode first aired on Fox in the United States on April 10 , 2012 . It features the introduction of special guest star Matt Bomer as Blaine Anderson 's ( Darren Criss ) elder brother Cooper , and the revelation of how badly injured Quinn Fabray ( Dianna Agron ) had been in the automobile accident that had ended the previous episode , " On My Way " . 
