Madrugada refers to the very early hours of the morning, specifically from midnight until dawn. It's a more poetic and specific term than just 'morning'.
In this song, the artist sings, "Soy esclavo de la madrugada" (I am a slave to the early morning). This phrase vividly captures the feeling of being up all night, perhaps due to insomnia, partying, or deep thought, and being unable to escape the solitude and reflections that often come with those quiet hours.
Natos y Waor's "Solo En Tu Cama" is a super honest look at a messy, on-again, off-again relationship. The singer wakes up alone, sometimes in his own bed, sometimes in hers, always with the same clothes from the night before. He admits, "A veces bebo para olvidarte / Si te olvido vuelvo a beber" [Sometimes I drink to forget you / If I forget you I drink again], which perfectly sums up the cycle he's stuck in.
He's a bit of a disaster, confessing, "No recuerdo el color de tus ojos / Pero dame otra oportunidad / Verás como la vuelvo a joder" [I don't remember the color of your eyes / But give me another chance / You'll see how I'll mess it up again]. It's blunt, funny, and shows he knows his own patterns. He's spent countless nights wandering Madrid, while she's been awake waiting for him, and he even asks, "¿Y yo te hago feliz?" [And do I make you happy?]. Despite his self-awareness and the chaos, there's a pull to her, even if he knows he has to leave again soon: "Si fuera por mí me quedaba a comerte la cara / Pero sabes que tengo que volverme a ir" [If it were up to me I'd stay and kiss your face / But you know I have to leave again].