Lesser of Two Evils

A fixed idiomatic phrase. The literal meaning (going to the grain) gives no clue to its actual use, which is to demand or offer directness in speech.

From pillar, used colloquially to mean catching someone in the act of doing something they shouldn't. The exclamatory form is often used alone as a triumphant cry.

Not slang per se, but carries a strong emotional weight that learners often underestimate. It implies a deep, almost aching nostalgia, stronger than simply extrañar.

While the literal meaning is transparent, in spoken Latin American Spanish it functions as a strong social insult directed at someone behaving in a morally unacceptable way, with a tone of disgust rather than clinical description.