Desvelo comes from the verb desvelarse, meaning to stay awake or to suffer from sleeplessness. It's a more evocative word than simply saying "no duermo" (I don't sleep).
In the song, the singer admits, "Pero en las noches me desvelo y no lo niego, envuelto en llanto" (But at night I stay awake and I don't deny it, wrapped in tears). This word powerfully conveys the emotional turmoil and sleepless nights spent regretting past actions, making it a memorable and impactful choice.
Rodrigo Tapari and Emanuel Cerrudo's "Decidido" is all about a powerful change of heart. The singer has been ignoring a call, maybe from a loved one or even a spiritual one, for a long time. He admits, "he sentido muchas veces tu llamado y me hago el sólido" [I have felt your call many times and I pretend to be solid/unmoved]. He's been hardened by the years without this connection, saying his heart "se ha endurecido a causa de los años que no he estado contigo" [has hardened because of the years I haven't been with you].
But now, he's had enough! He can't resist anymore and is ready to open up completely. He declares, "he decidido abrir mis puertas hacia ti, toma mi corazón yo te lo doy" [I have decided to open my doors to you, take my heart, I give it to you]. This isn't a temporary thing; he's firm that "sin que haya nada que cambie mi opinión" [without anything changing my opinion] because this feeling brings him "paz y me hace ser feliz" [peace and makes me happy]. It's a beautiful declaration of finally embracing something that brings joy and peace after a long period of resistance.