Place it as the closing reaction after the unbelievable claim has played in full, then follow it with a record scratch for emphasis or a crowd laugh to underline the disbelief. Keep it last so the reply lands as the final word.
Bu Ses Hakkında
This is a voice clip of Egyptian actor Hany Ramzy saying the Arabic phrase that translates as I believed you and I am convinced, lasting just under ten seconds. It feels playfully sarcastic rather than sincere, turning polite agreement into a teasing signal that the listener is not fooled and is enjoying the exaggeration.