Ellen DeGeneres knows that BTS learned how to speak English by watching Friends and she also knows that their fans really love them. Therefore, she killed two birds with one stone and had the boy band hide out on the Friends set on the Warner Bros lot as their fans recreated a scene from the sitcom.
When it is revealed that the 7 rockers are in the same room with them, all the girls screamed like girls meeting their teen idols. And yet none of them ran over and attacked them which seems really odd to me. Does BTS have something against PDA?