Puerto Rican rapper Alvaro Diaz and producer Tainy built this one around a late-night hookup fantasy, and the title says it straight: a fatal fantasy. He is fixated on a woman who "tiene fotos conmigo y no sube nada" (has photos with me and posts none of them). The chorus is the slow-burn part: "Que yo llevo toda la noche mirándote" (I've been watching you all night), and then the watch decides for them, "ya llegó la hora de irnos, dice el Cartier" (it's time to go, says the Cartier).
The verses are packed with Puerto Rican slang and pop-culture name drops. "Gatúbela" is Spanish for Catwoman, stretched into "Gatúbela-túbela-túbela" for the beat. "Tú eres una KAROL, una bichota" (you're a KAROL, a boss lady) nods to Karol G and her song "Bichota", where a bichota is a big-shot woman who runs things. "Y nos matamos, River con Boca" (and we go at each other, River against Boca) borrows Argentina's fiercest football rivalry, River Plate vs Boca Juniors, as an image for how intense they get. It is very explicit in places, so treat it as an adults-only lesson.
Slang to learn: "Guarden lo' celus" (put away the phones), where celu is short for celular, and "se hace la loca" (she plays dumb), literally "she acts like the crazy one".