Traicionado means "betrayed." It's a strong and emotionally charged word that immediately conveys a sense of deep hurt and broken trust.
In the song, the singer uses this word to describe how her partner not only hurt her but also "betrayed the one above" ("al de arriba ha traicionado"), implying a betrayal of a higher power or moral code. This adds a layer of gravity to his actions, making it a powerful and memorable word in the context of the song's narrative of heartbreak and deception.
The whole song is one phone call. Yuridia opens with "Amiga, te pido un favor" (Friend, I ask you a favor), and the favor is bigger than it sounds: come pick me up, and when he turns up, you deal with him. "Ábrele la puerta" (Open the door for him), she tells her friend, and then "Que se vaya" (Let him leave). She never once speaks to him herself. That is the whole design of the song. She knows she cannot be in the room with him.
What he actually did stays unnamed, which makes "Dile que yo ya me enteré lo que ocultaba" (Tell him that I already found out what he was hiding) sting more than a detailed accusation would, especially set against his claim to be "un hombre de palabra" (a man of his word). Then she goes where most breakup songs stop: "Puede que me haya lastimado / Pero al de arriba ha traicionado" (He may have hurt me, but he has betrayed the one above). Her own hurt is the lesser charge. The best line is saved for last, and it is quietly brutal: have him hand over the house keys, because "yo sé que él ni podría / Sostenerme la mirada" (I know he couldn't even hold my gaze). She does not want a conversation. She wants an exit she never has to watch.