Domino suspects that El Mariachi is actually Azul, and surprises him while he is in the bathtub by thrusting a knife into the water and demanding that he sing. His improvised song is about how he is looking at a beautiful woman and may soon suffer a castration.
The completely random quick-cut to a dog wearing giant sunglasses!
The fact that El Mariachi's narration has him claim that the turtle was more beautiful than Domino, "of course". (O...kay...?)