Desvelo literally means "sleeplessness" or the state of being unable to sleep. It comes from the verb velar, which means to stay awake or to watch over.
In the song, the artist sings about the "noches de desvelo" (sleepless nights) he shared with his ex. It's a poignant and romantic word that implies more than just staying up late; it suggests being kept awake by deep conversation, passion, or intense emotion, capturing the essence of what he's lost.
Junior H gives us a perfect Corrido Tumbado for when you're heartbroken but still have to get that money. He's trying to bury his feelings under stacks of cash and parties, but it's not working at all. He tells his ex, "Si el dinero me miran gastar / Es que así me acostumbré a ganar" (If they see me spending money / It's because I got used to winning like this), but immediately admits the real reason for his wild lifestyle: "Y si a diario me miran tomar / Es que no te he podido olvidar" (And if they see me drinking daily / It's because I haven't been able to forget you).
He's caught in a loop. He parties with other women to forget her, but then finds her perfume in his car and calls her over and over. He blames her for his excesses, saying he got lost in "drogas, mujeres, las armas, el dinero" (drugs, women, weapons, money) because she left. He knows he's not the romantic type she wanted, calling himself a "vago que por tus besos moría" (a bum who would die for your kisses). The song ends on a surprisingly mature note. After all the drinking and denial, he admits, "Estaba a punto de salir a buscarte / Pero si eres feliz tengo que respetarte" (I was about to go look for you / But if you're happy, I have to respect that).