American singer Katty Perry angered some BTS's ARMY after she made a joke during the recent 2019 Jingle Ball that suggests the K-pop group's fans are mostly underage children. In return, many BTS's fans left the event early while those who stayed gave the "Firework" singer a "black ocean." 

BTS opened the 2019 Jingle Ball in Los Angeles over the weekend. The group performed their hit songs "Mic Drop," "Make It Right," and 'Boy With Luv." Throughout BTS's performance, their fans actively waving their lightsticks, chanting the members' names, and singing along with them. 

After the performance of Billboard and American Music Awards' Best Duo/Group winner, their fans stayed to watch the other featured artists for the night. BTS was followed by Billie Eilish. After the "Bay Guy" singer, it was Katy Perry's turn to hit the stage.

The singer, however, made a comment that made many of BTS's fans furious and left the show. Perry said many in the audience should be happy since they have to get to stay up late past their bedtime. Unfortunately, the venue was packed with BTS ARMY. 

Perry's joke didn't sit well with the ARMY. Apparently, fans took her remark as "mocking" the fandom while some find it offensive. 

Those who stayed in the venue didn't react on Perry's performance and gave her a "black ocean." It is a phrase that is used in K-pop when the audience turned off their lightsticks when someone is performing on stage. 

Many also took to Twitter to slam Orlando Bloom's fiancée. Some claimed that the singer is being ignorant about how diverce BTS's fanbase in age, gender, and background.

Others shared a video of an elderly couple in one of BTS's concerts to show how diverse the group's fans are. In the clip, the female elderly is seen waving her ARMY bomb while the septet is singing "DNA" in the background. Another fan posted a clip of the crowd during the performance of BTS in Good Morning America's 2019 summer concert series in May. 

Meanwhile, some of the fans also defended Katty Perry. They believe the singer just made a light-hearted joke. Both BTS and Katy Perry have not yet respond on the matter. 

BTS's ARMY raised their lightsticks again in 2019 Jingle Ball in LA when Halsey re-appeared on stage. Prior to her own performance, Halsey joined BTS on stage in their single "Boy With Luv."