Person 2 used the term "S.O.B.L" because they thought Person 1 was stupid for not knowing what "BTS" stood for, and laughed so hard, that they physically spat out blood. (Of course, you do not have to spit out blood to use this term, but in this case, someone actually did spit out blood from laughing so hard.)
Acronym for "Automatically Suspect Since He Obviously Lacks Empathy"; refers to any obnoxious/arrogantdude who just can't seem to be reasonable or considerate, and so nobody trusts him or gives him the benefit of the doubt in any social setting.
That new store manager is a total a.s.s.h.o.l.e., and so the staff is edgy and nervous as a result.