AJ McLean, Joey Fatone Dish on NYE Show, Bromance, Potential *NYSNC Reunion

Boyband stans, rejoice! Backstreet Boys’ AJ McLean and *NSYNC’s Joey Fatone are teaming up for a killer New Year’s Eve performance -- and they're spilling all the tea about it to TMZ.

AJ and Joey dropped by "TMZ Live" today, raving about how their last boyband mash-up was such a hit, it sparked their upcoming show -- AKA a heartfelt love letter to their fans.

You’ve gotta watch the video -- AJ and Joey’s passion is off the charts, and it’s clear their energy is all thanks to the die-hard fans who’ve been vibing to their tunes all these years.

Even though they came up in rival boybands, AJ and Joey’s bromance is real -- watch the video and you’ll see Joey explain how their deep connection actually comes from their shared experience in the pop world.

AJ’s clearly been living the Backstreet dream since their heyday, but the convo quickly shifts to *NSYNC’s long-awaited reunion -- spoiler alert: there’s some good news ... and some bad news.

He spills all the juicy details on whether *NSYNC will be tearin' up the stage soon or not -- and trust us, you won’t want to miss this!

BTW, you can catch Joey and AJ performing on New Year's Eve at House of Blues Orlando, in Florida.

Catch the full interview on "TMZ Live!" ... check your local listings.