In the song "Tu Vacío (Intro)" by Niños Perdidos, the singer is questioning why their partner continues to lie when they know the truth and why they call when they have no intention of returning. The lyrics suggest that the singer is tired of being manipulated and wants their partner to face the reality of their own emptiness and learn to love themselves sincerely. The chorus emphasizes that the singer will not forgive their partner and that they need to find their own healing and introspection, rather than seeking validation and comfort from others. The overall theme of the song is about self-worth, honesty, and moving on from toxic relationships.