Aurora is a beautiful and poetic word for "dawn". While amanecer is also used for dawn or sunrise, aurora evokes a more literary and romantic image, named after the Roman goddess of sunrise.
In the song, Enrique Iglesias pleads, "Que al llegar la aurora no me digas adiós" (That when the dawn arrives, you don't say goodbye to me). He uses this word to create a scene of desperate romance, fearing that the night of passion will end with the first light of day.
This song is called "Loco" for a reason! It means "crazy" in Spanish, and that's exactly how the singer feels. He's so terrified of his lover leaving him that he's losing his mind. The whole song is a desperate, passionate plea for her to stay, and he's not afraid to be dramatic about it.
He starts by begging on his knees, not just to his lover, but to the moon itself: "Te pido de rodillas / Luna no te vayas" (I'm begging you on my knees / Moon, don't go away). He mixes these pleas with some pretty intense threats, warning her, "No te perdonaré / Si me dejas solo" (I won't forgive you / If you leave me alone). He feels his emotions are like a storm that "lo revuelven todo / Y me vuelven loco" (messes everything up / And drives me crazy). It's a powerful mix of love, obsession, and the fear of being left with nothing but pain.