Put it at the exact reveal in your edit, right after the item fills the frame. Follow it with a vine boom sound effect for the reaction beat, then cut to the other person's reply or a still of their face.
About this sound
A short Spanish voice clip, just under six seconds, built around a single spoken line: 'esta tu no la tienes.' The delivery feels taunting and boastful, turning a simple brag into a playful put-down that listeners instantly read as sarcasm, mockery and smug one-upmanship.