Brian Littrell Shoots Down Joey Fatone, Backstreet-'NSYNC Ain't Happening

Brian Littrell's reaction to Joey Fatone suggesting the Backstreet Boys and 'NSYNC come together in one super boy band is pretty simple -- Bye, Bye, Bye ... it ain't happening until you get Justin Timberlake.

We got the BSB singer Thursday at LAX, and he absolutely destroyed Joey's dreams of the pop pairing that, honestly, would be Larger Than Life. Brian's point is ... right now BSB is bringing a lot more to the table than 'NSYNC can.

He's got a point. Backstreet was Grammy-nominated this year, starred in a Super Bowl commercial with Chance the Rapper ... AND they have a Vegas residency. All of that equals relevance.

But watch, Brian does offer a small ray of hope.

If Joey really Wants it That Way, all he's gotta do is get JT on the horn ... and then wait another 10 years or so. LOL!!!