This is a love song from the side of the friend who never says anything. Every time he is near her, "no digo nada" (I say nothing), because someone else "roba tu mirada" (steals your gaze). He can watch her smile, but "duele ver que no es a mí" (it hurts to see it isn't at me). Ouch.
Instead of confessing, he hides it "en mis latidos" (in my heartbeats) and begs a hopeless dream to make her dream of him. The chorus is where he stops pretending to be calm: "Es mi corazón que no es normal" (It's my heart that isn't normal) and "Te quiero hasta el infinito, aunque estés con alguien más" (I love you to infinity, even though you're with someone else). Then comes the title line, "Pero yo puedo esperar" (But I can wait). It is a patient, slightly hopeless kind of devotion, and the Spanish is clear and repetitive, great for practising aunque (even though) with the subjunctive: aunque estés, aunque no pueda.