The singers had previously hung out at the American Music Awards.
Ansel Elgort and BTS' RM and V jam out!
The Baby Driver star shared a video on of the K-pop superstars listening to his latest single, "Supernova," while Elgort dances in the back.
"When I showed Tae and RM an early version of Supernova in Seoul this summer ? it’s finally out now!" Elgort tweeted alongside the 15-second clip. The trio had previously reunited at the American Music Awards in November, where BTS performed "DNA" in their U.S. television performance debut.
During BTS' AMA performance, the camera showed Elgort happily recording his pals on stage. He also shared a pic with all seven members and his girlfriend, Violetta Komyshan.
The singers first met at the Billboard Music Awards in May and had their second run-in in South Korea while the actor was promoting Baby Driver.
"Much ❤️ they are really the nicest dudes, @BTS_twt thanks for coming and supporting #BabyDriver I can't wait to hear your album guys," Elgort tweeted in August of last year.
There's no doubt that BTS has taken the U.S. by storm. ET caught up with the international group at their AMA rehearsals, where RM explained the significance of their performance.
"I mean, AMAs, like, we watched the videos on YouTube when we were like 15, 13, so we cannot believe that we have our first time ever U.S. televised debut on the American Music Awards," he said. "It is going to be, I think, a new opportunity to reach out to the new fans and show them that our music and performances is something [they] can relate to, even if it's in Korean."
"[We're] going to do it like we always have been, so we are ready," RM insisted.
See more on ET's interview with BTS in the video below.