Wait, does it not stand for “behind the scenes” wrt the K-pop group?

I thought it stood for Boppan Tangnam Style.

Nah, for the Kpop group it's a shortening of the group's full Korean name Bangtan Sonyeondan which in English translates to "Bulletproof Boy Scouts". Though in recent years they apparently also added "Beyond the Scene" to try to show how they've grown since they first began.

It does stand for behind the scenes, but it is also a popular kpop group, the bangtan boys (bangtan sonyeondan in Korean) (everybody just calls them BTS)

It stands for Bangtan Boys