Inolvidable is a beautiful and powerful adjective that means 'unforgettable'. It's formed by adding the prefix in- (un-) to olvidar (to forget), perfectly capturing a sense of lasting memory.
In the song, which is named after this concept, Bad Bunny sings "Y fuiste tú mi baile inolvidable" (And you were my unforgettable dance). He uses this word to describe a past love, elevating a shared memory to something timeless that, despite the pain of the breakup, he will cherish forever.
Puerto Rican superstar Bad Bunny frames heartbreak through the metaphor of a dance floor in "BAILE INoLVIDABLE". Instead of hiding his grief, he leans straight into it with the opening realization that he thought they would grow old together ("Pensaba que contigo iba a envejecer"), but now that dream only belongs in another lifetime. He compares life to a party that eventually ends, calling his lost love his unforgettable dance ("La vida es una fiesta que un día termina / Y fuiste tú mi baile inolvidable"). Even though he admits he can sleep with anyone he wants, he only actually wants to wake up next to this one person ("Yo con cualquiera me puedo acostar / Pero no con cualquiera quiero despertar").
Bad Bunny fills the track with playful Caribbean slang to contrast the heavy sadness. He switches to the formal "usted" (you) to show deep devotion before slipping into wild compliments, calling his ex "Mi diabla, mi ángel, mi loquita" [My devil, my angel, my crazy girl]. He also uses the Puerto Rican slang word "bellaquito" (horny or aroused) when remembering how she looked at him ("Cómo tú me mirabas, bellaquito me ponía"), proving that his memories are intensely physical as well as romantic. It is an honest, bittersweet track about carrying someone's memory forever because they were the one who taught you both how to love and how to dance ("Tú me enseñaste a querer / Me enseñaste a bailar").