Decepcionas comes from the verb decepcionar, meaning "to disappoint." It's a strong emotional word that captures the feeling of letdown and disillusionment.
In the song, the artist sings, "Por más que disfraces las cosas, más me decepcionas" (The more you disguise things, the more you disappoint me). This highlights the pain caused by insincere actions and hidden truths, making it a poignant and relatable word in the context of a failing relationship.
Gerardo Coronel builds "No Se Dice" around one trick: correcting the polite version of a breakup with the blunt one underneath it. The chorus interrupts itself every time. "No se dice, 'Estoy confundida'" [you don't say, "I'm confused"], he sings, and then, "Se dice, 'No siento lo mismo, ya nada es igual'" [you say, "I don't feel the same, nothing feels the same anymore"]. Two ways of saying the same breakup, and he only trusts the second one.
The verses explain why he's done letting her off easy: "Los vicios, la falta de besos" [the vices, the missing kisses], "uno que otro pleito innecesario" [one fight after another that didn't need to happen]. His ask is plain, "Di lo que es de una vez" [just say what it is, once], and the song closes on the same flat line twice, "De todos modos, esto ya no da pa' más" [either way, there's nothing left to give here]. He repeats it because she still hasn't said it.