Little Mix are a very grateful bunch...and also very, very tired.

The UK troupe is currently in the midst of a massive global promotional tour in support of their latest single "Black Magic," as well their upcoming studio album, Get Weird.

And, after a super casual invitation onto the stage to sing with Taylor Swift over the weekend on the 1989 Tour (sure, who isn't one of Tay's BFFs?), the ladies touched down in NYC this week for a very special celebration of the fourth anniversary of their 2011 formation.

To ring in the occasion, the girls woke up bright and early at 4 AM this morning (blurgh) to get ready to hit the stage for the TODAY Show Summer Concert Series, only to be immediately ushered inside Rockefeller Center for an intimate AOL #BuildSeries livestream, hosted by TODAY Queen Hoda Kotb, with a whole bunch o' excited Mixers (and also me) eagerly awaiting their arrival.

And, oh, the emotions! The memories! The sleeplessness! Perrie and Jade warned that there would be tears at the start of the livestream, and sure enough, the girls basically all took turns weeping in front of the entire world.

During their interview, the young ladies reflected on the entirety of their time together as a group: from their UK X Factor auditions (if you're new here, they're the first group in the history of the UK series to win a season) to shooting their dorky, Craft-inspired video for "Black Magic," to their enduring sense of sisterhood (girl Power for the #selfie age!) to, of course, their ever-loyal Mixers.

But once a montage of friends and family congratulating them on their success appeared on the monitors, including cameos from Cher Lloyd, Kelly Rowland and Simon Cowell? Forget about it. Not a single eye was dry on that stage. Guh! (Also, Leigh-Anne had a brief eyelash malfunction that required some on-stage makeup magic. LIVE TV!)

The nostalgia/eyelash glue-induced tears didn't stop once they were done talking, either: While in the midst of their acoustic set, which included impressively high-spirited renditions of "Black Magic," their killer cover of Katy Perry's "E.T." from their X Factor UK days and their second #1 UK hit "Wings," Perrie broke down in tears at the tail-end of a brand new Get Weird song, "The End."

Naturally, the press has already run rampant with the story, speculating that the break-up anthem hit a little too close to home considering her recent split with Zayn Malik. Or, uh, maybe she was just really, really tired? Unclear. In any case, she was back in action after a quick, loving huddle (and shrieks from the audience!) from her ever-loyal Little Mix BFFs.

Tears, eyelash tragedies and lots of sleep-deprived giggles — that is how you do a proper livestream. Congratulations again, ladies!

PLUS: We've got a very special "Black Magic"-themed Magic 8 ball to giveaway to one lucky lil' Mixer. All you've got to do is follow us on Twitter and RT this tweet below!

Good luck!

Check out the interview stream below, as well as behind-the-scenes footage and some clips of the acoustic performances on our Instagram.

Taylor Miller
Taylor Miller

Check out the meaning behind the name Little Mix: