Fallon took The Tonight Show to Central Park on Thursday for the first time ever, shooting an episode on an outdoor stage in the middle of the historic New York City locale, and to celebrate the special occasion he teamed up with the singer for a goofy pre-taped segment.
Donning bad wigs, laughably fake mustaches, dark glasses and loose-fitting black suits, Fallon and Bieber headed out into Central Park for a segment the host called "Musical Photobomb."
Both stars wore earpieces playing Bieber's hit "What Do You Mean?" and proceeded to lip sync and dance to a song no one else could hear behind and around unaware and unsuspecting random park goers.
While Fallon in disguise still looks very much like himself, Bieber actually managed to disappear into his hilariously bad get up, which made him look remarkably like a slender mid-1970s Sonny Bono.
From dancing in the background behind a group of people enjoying a picnic to busting out choreographed moves on some park steps next to a man jamming on a guitar, the pair made total spectacles of themselves, and yet managed to remain relatively unnoticed.
Throughout the whole stunt, Bieber was smiling from ear to ear and the recently engaged pop superstar seemed to be having an amazing time dancing on the tops of traffic bollards or hip-thrusting while playing a pan flute.
It wasn't until the very end of their day out -- which seemed to take them throughout the entire park -- that Bieber and Fallon pulled off their floppy wigs and poorly attached mustaches to reveal their true identities, at which point they posed for photos with his legion of fans.
The sketch was shot nearly a month ago, when photos of Fallon and Bieber in their surprisingly successful disguises began popping up on social media.
However, this wasn't the first time the "Sorry" singer managed to go unrecognized while out and about in New York City. Back in July 2016, Pokemon Go fans were so excited about the captivating new game that they didn't realize that Bieber was playing right alongside them -- and that was without him even wearing a disguise at all!