This is a breakup song you can dance to, which is very cuarteto. The singer admits he thought "contigo iba a envejecer" (I was going to grow old with you), and now he can only hope for it "en otra vida, en otro mundo" (in another life, in another world). In this one, all that is left is "verte en el atardecer" (to see you in the sunset), or later, looking "pa'l cielo" (up at the sky, "pa'l" being a casual squeeze of "para el") to see if she falls from it.
The chorus is the best part. "Si me ven solo y triste, no me hablen" (if you see me alone and sad, don't talk to me), and then, oddly honest, "soy culpable" (I'm the guilty one). Life is "una fiesta que un día termina" (a party that ends one day), and she was "mi baile inolvidable" (my unforgettable dance). The outro keeps going: "no te puedo borrar" (I can't erase you), "me enseñaste a bailar" (you taught me to dance). Sad words, happy rhythm, and that contrast is the whole charm.