"Perfidia" is a classic Latin American bolero about heartbreak and betrayal. The title itself means "perfidy," treachery or unfaithfulness, and that word sits at the center of the song.
The singer is alone and in pain, insisting that no one else understands what they're going through. They say they sing instead of crying, because singing is the only way they can release their sorrow. They picture the sea as a mirror of their own heart, one that has watched them weep again and again because of their lover's betrayal.
No matter where they look, they can't find the person who left them. They've lost interest in anyone else's affection, since the lips that used to kiss them no longer want to. The song closes with the singer wondering where their former love has gone, what new adventures they might be having, and how far away they now are.
It's a simple, aching song about love that ends in betrayal, full of longing, sadness, and the impossible search for someone who has already moved on.