The origin of this specific recording is not widely documented, so it circulates mainly as a standalone reaction clip on soundboards and in short form video edits. Its popularity comes from the phrase itself, a casual American way of saying someone is not being truthful, shortened here to BS'ing. Because the delivery is so short, editors reuse it as a drop in punchline that needs no setup or context. It has become a go to shorthand for disbelief, teasing, and playful arguments among friends online.