Vaginas is a highly unusual and striking word to find in a song, especially in a context that seems to be about sadness and longing.
While the literal translation is
This song feels like a sad birthday party where the person you really want to see simply does not show up. The singer says it clearly: it is his birthday, “es el día de mi cumpleaños” [it is my birthday], but instead of feeling happy, “no me siento una alegría” [I do not feel any joy]. Everyone else seems to be celebrating and laughing, but he is stuck in his own sadness because the person he calls “mi amor” [my love] and “mi mujer” [my woman] is missing. The contrast is strong: a day that “necesita” [needs] everything to be perfect, and yet “tú no estás” [you are not here].
What really hits is how lonely he feels in the middle of a party. There is this image where “para mí todos ríen” [for me, everyone laughs] while he stays behind, “yo me quedo con la mano” [I stay with my hand (empty / hanging there)], like he was left waiting for someone who never arrived. The repeated question “mi amor, dónde estás” [my love, where are you] turns the whole birthday into a search for that one person. It is a simple idea, but very direct: a special day means nothing to him if she is not there, because in the end “bueno pero sólo a ti” [well, but only you] is the one he really cares about.