The line comes from the Showtime series Dexter, which premiered in 2006, where Sergeant James Doakes, played by Erik King, repeatedly confronts Dexter Morgan with deep suspicion. His blunt delivery turned the phrase into his signature catchphrase across the early seasons. Clips circulated on YouTube and Vine as a reaction sound, then spread through meme edits and soundboards as the ultimate caught in the act moment. It remains popular as a Dexter meme because the anger is so direct that viewers understand the joke even without knowing the original scene context intimately.