Just how gaga is CBS when it comes to promoting the upcoming 53rd Annual GRAMMY Awards airing February 13 at 8PM? Well, put it this way, not only will Justin Bieber be pulling double duty on both the LATE SHOW WITH DAVID LETTERMAN and CSI we’re he will reprise his role as a troubled teen Jason — HOW I MET YOUR MOTHER fans should expect fireworks. Specifically from California Gurl Katy Perry, who will drop by the February 7th episode as Honey, a naive cousin of Zoey (Jennifer Morrison) who gets Barney to open up about his life. More first look photos of which can be found after the jump. 
