Nostalgia simply slammed into Vegas … ‘trigger when New Children On The Block kicked off their Proper Stuff residency, members of a rival boyband crashed the stage — and the group misplaced it!

Catch the clip — NKOTB have been hyping up the group final weekend on the Park MGM, asking who needed to marry them again within the ’90s … and whereas followers screamed, Backstreet Boys’ Howie Dorough popped up with a cheeky banner that learn, “I Do.”

Howie later pulled up with AJ to crash the stage … and it was nothing however boy band bromance — hugs, laughs, and main Nineteen Nineties nostalgia as they embraced NKOTB like long-lost brothers.

For those who have been anticipating a boy band showdown — assume once more. Even with BBs launching their Millennium Sphere residency later this month, each teams proved there’s greater than sufficient room (and love) to go round on the Vegas Strip.

However with NKOTB already kicking issues off with a bang, you may guess it’s lit a fireplace underneath the Backstreet Boys — and sources inform us they’re grinding laborious, rehearsing 12 hours a day, 5 to six days every week, to gear up for his or her massively anticipated Sphere takeover.