Did the ecstatic fans in the audience give it away? The shout-outs from the cast and Emma Stone? Or was it the seemingly endless conversation flooding Twitter? Whatever way: It was hard to miss the excitement that was K-pop sensation BTS' "Saturday Night Live" appearance.

The #BTSxSNL hashtag permeated Twitter late Saturday night into the early morning (and floated around leading up to the show, too.) The group performed two songs including newly-released "Boy With Luv," which they will perform with Halsey at the Billboard Music Awards on May 1, marking "the world TV premiere performance" of the song.

Fans were quick to shower the group with praise on social media.

"THIS CHOREOGRAPHY. IT’S SO HAPPY RELAXED AND JUST ???? HAPPY??? I’M IN LOVE THIS IS TRULY THEIR BEST TITLE TRACK EVER," one user wrote.

Another wrote: "I’m crying I can tell our boys were a bit nervous but still @BTS_twt was amazing. They killed it. LIVE KINGS!!!" A fellow fan countered, "Remember the boys’ first performance on american tv at the AMAs in 2017.... how nervous they looked.... and today they had a comeback stage on snl looking SO happy and confident. proud is an understatement."

BTS unveiled the Halsey-featuring single on Friday, as part of their new EP "Map of the Soul: Persona," along with the music video for the song that they've been teasing on social media.

The group presented at the Grammys earlier this year and turned many a head on music's biggest night. They were the most tweeted-about artist in the U.S. in 2017.

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Contributing: Maeve McDermott, Patrick Ryan