Cuernos literally translates to "horns". However, in Spanish, the phrase "pegar cuernos" is a very common idiom that means "to cheat on someone".
In this dramatic bachata, Romeo Santos accuses his partner of infidelity, singing, "pegaste cuernos a su papá" (you cheated on their dad). Learning this expression is key to understanding the raw emotion and betrayal at the heart of many Latin songs.
Romeo Santos takes bachata straight into absolute melodrama here, turning a bar into an emergency room for his broken heart. He kicks things off by ordering another glass of Brugal—a famous Dominican dark rum—and vows to drink until the stock runs out. The setup is wild from the first line: he is telling everyone to call an ambulance because he plans to bleed out emotionally right there in the tavern ("que en esta cantina me voy a desangrar" [that in this bar I'm going to bleed to death]). It is over-the-top, loud, and messy, matching the exact feeling of an ugly breakup in public.
His anger spirals into pure contradiction. He shouts that he loves and hates his ex at the same time, bluntly adding: "Creo en Dios, pero te quiero en el infierno" (I believe in God, but I want you in hell). He even drops the Dominican street phrase "pegaste cuernos" (you put horns on / you cheated on), venting that she ruined their family and leaving instructions to tell their daughter that her mother was a disgrace. By the end, he is drunk-talking the bartender, refusing to let anyone grab him, and screaming that his ex will have to pay for the drinks and his funeral.