Bilirrubina is the Spanish word for "bilirubin," a yellowish substance made by the body. It's a very unusual and scientific word to find in a pop song, which makes it incredibly memorable!
Alvaro Soler sings "la bilirrubina corre por mis venas" (bilirubin runs through my veins) to poetically describe a powerful rush of love and happiness. He's also making a clever nod to the iconic song "La Bilirrubina" by Juan Luis Guerra, where a lovesick man comically asks a doctor to check his high bilirubin levels caused by seeing the woman he loves.
Spanish singer Alvaro Soler treats us to a sweet reminder to quit stressing about what is already done. His central message is right in the title: the word regalo means present or gift, playing on that classic idea that today is a gift worth enjoying right now. He promises the full moon ("Le he prometido a la luna llena") to leave the past behind and give his partner a genuinely good life. You get to drift through dreamy, cozy scenes with him: sipping morning coffee in a Paris hotel room, lounging in pajamas by a garden window, sharing a chilled tinto de verano (a popular Spanish mix of red wine and lemon soda), and listening to Cuban music led by Ibrahim Ferrer's vocals ("la voz de Ibrahim").
He also plays with words in clever ways you should know as a learner. When he sings "la pena no vale la pena", he is using the noun pena (sorrow or grief) alongside the common idiom valer la pena (to be worth the trouble), essentially declaring that sadness simply is not worth your time. Then he drops a wonderfully dramatic line: "la bilirrubina corre por mis venas" ("bilirubin runs through my veins"). Bilirubin is a real liver pigment linked to jaundice, but in Latin pop culture, it is a famous nod to Juan Luis Guerra's classic hit about being lovesick to the point of physical illness. Soler is saying his heart is racing so fast with love that he is ready to gamble everything on this life with you.