To show your true colors, to reveal who you really are underneath the facade. Literally "to show the loose threads," like cheap clothing that falls apart and exposes what is underneath. It is used when someone drops their mask and their real intentions, flaws, or character come through. Common across Latin America, especially when someone who seemed trustworthy turns out to be shady or selfish.

Pineapple in Argentina and Uruguay — the word comes from Guaraní and is the go-to term in the Río de la Plata region. Same fruit, different name from the rest of the Spanish-speaking world.

Avocado in Argentina, Chile, Peru, and Uruguay — the Quechua word for the same creamy green fruit. The 'palta vs. aguacate' debate is one of the great divides of the Spanish language.