Place it right as the disappointed face appears, before you reveal the outcome. Follow it with the Emotional Damage Meme Sound for a second hit, or swap it for the Sad Meow Song when you want the same beat from a different angle.
About this sound
This is a three-second, heavily distorted take on the sad background music linked to SpongeBob, pushed into a loud earrape style. It feels ridiculous rather than truly sorrowful, turning a small letdown into parody heartbreak. It comes from SpongeBob SquarePants, the animated television series.