Piquetúa' is a fantastic example of Puerto Rican slang that you won't find in a standard dictionary. It's an adjective used to describe someone, usually a woman, who has a lot of piquete—a unique sense of style, confidence, and swag.
In the song, Bad Bunny sings "La baby es piquetúa', por eso roncamo'" (The baby is stylish, that's why we boast). He's admiring her confident flair and saying that her amazing style is something worth showing off.
Bad Bunny hits the gas pedal right from the start in "120", speeding at 120 miles per hour just to see someone who got inside his head: "Por ti me monto en el carro y meto ciento veinte" [For you I jump in the car and hit one hundred and twenty]. He calls her a psychic snake who entered his mind, daring him to go against traffic to meet up. It is fast, reckless, and hilarious in its honesty. At one point, he even begs her to hold off undressing until he puts his glasses on ("No te quite' la ropa sin ponerme los lentes" [Don't take off your clothes without me putting on my glasses]) simply because he wants to see clearly.
From there, he swaps between flexing his status and keeping this late-night fling completely hidden. He compares himself on an instrumental track to a luxury Bugatti car stuck in its own lane, joking about his homes in Puerto Rico and Beverly Hills just in case the NBA's Los Angeles Lakers call him up to coach. Puerto Rican slang flies everywhere here: he calls his partner "piquetúa" (arrogant or full of swagger), brags that "roncamo'" (they show off, literally 'snore'), and admits "a to' el mundo le pichamo'" (they ignore everyone else). It ends with zero romance. They get what they want in private, avoid saying "te amo" [I love you], and casually return to normal life.