"NGL" is an acronym that typically stands for "not gonna lie," but it also has a unique meaning in the context of BTS RM's album "RPWP." In this album, "NGL" stands for three track titles: "Nuts," "Groin," and "Lost."
BTS ARMYs use this acronym to express a sense of excitement in casual usage, similar to the expression, "loosing their wigs," but instead they are expressing that they lost their nuts and groin.
Omg did you hear the new RM's new album?
Ngl!