Watch the Backstreet Boys perform 'Thong Song' as a barbershop quartet

Backstreet Boys, who have never broken up or gone on hiatus like other '90s boy bands, have a new album out, DNA, and a new tour. Backstreet’s back, all right? Perhaps it’s hard to believe that a boy band would have longevity or staying power in a business that has changed so rapidly in the last 20 years, but these guys don’t care who you are, where you’re from, what you did—as long as you love them. And all the boys (Kevin, Howie, Nick, AJ, and Brian) none of whom have aged in the past 20 years (*drools*), stopped by The Tonight Show Starring Jimmy Fallon on Tuesday night to sing a few songs from back in the day.Did they sing "Shape Of My Heart?" Or perhaps "I’ll Never Break Your Heart?" Maybe "Quit Playing Games With My Heart?" Please tell us it was a heart-themed song!Prepare yourselves fam, because as the quintuplet stepped out on stage, along with Jimmy, in striped Ragtime jackets the colours of barbecue condiments, white slacks, straw hats, and big red bowties, it became obvious they were going to sing a bit of A Capella barber shop but we're pretty sure it a song choice no one could have predicted. Lo and behold, the harmonizing gents proceeded to give us a song that had dumps like a truck and thighs like what—yup, it was Sisqó’s ‘Thong Song.’ We have to admit it, the 1999 jam is kind of giving us life over here.[video_embed id='1895546']RELATED: These stars dropped new music today[/video_embed]Speaking of time capsules, Late Night with Seth Meyers shoots in the same building as The Tonight Show, and as RuPaul sat down with Seth to chat about his weekend hosting stint at SNL, he mentioned that he just bumped in to the Backstreet Boys in the elevator. As he tells it, the queen of drag then began singing "Show Me The Meaning of Being Lonely" to the NBC page accompanying him who stared back blankly. “He had no idea what that song was... one of the greatest pop songs of all time," Ru confirmed. Kids these days.Watch The Tonight Show Starring Jimmy Fallon weeknights at 11:35 p.m. ET on CTV2.[video_embed id='-1']BEFORE YOU GO: James Corden and Rebel Wilson presented an Oscar as cats[/video_embed]