We'll give you a hint: IT'S NOT BECAUSE OF JUSTIN BIEBER!
Though many outlets speculated Selly was crying during her ballad, Love Will Remember, because the tune is believed to be about her ex-boyfriend — the Come And Get It singer was actually shedding tears for her fans!
She really wanted to take Instagram pictures with them after the show, but wasn't allowed! Awe!
The former Disney star shared the (above) sad pic of herself holding up a Brooklyn T-shirt with the caption:
"Never ended such a beautiful show in tears because they wouldn't allow me to Instagram tonight. Completely heartbroken and pissed. Thank you SO much Brooklyn. Ill be stopping outside Letterman tomorrow to make it up if you can make it. I love you guys more than you know. Promise."
And sure enough, Miz Gomez delivered!
Ch-ch-check out the singer posing with fans outside Letterman (below)!
Is she not THE BEST?!
[Image via Instagram.]