The origin of this specific recording is not clearly documented, but the phrase itself is a long standing piece of American profanity combining shit eating, meaning smug or contemptible, with S.O.B., short for son of a bitch. Clips built around extreme one line insults like this spread on soundboards and in meme edits because they are instantly quotable and need no context to land. This version stays in use for its full, uncut delivery, which makes it useful as a standalone reaction rather than a quick sound bite.