Deletreo literally means "I spell out". It's the title of the song and a key element of the chorus, making it highly memorable and central to the song's theme.
In the song, Nicky Jam uses "deletreo" in a playful and provocative way, spelling out words like "P-E-R-R-A" (bitch) and "L-O-C-A" (crazy) to describe the women he's with. This unique use of spelling out words in a reggaeton context makes it an interesting and engaging word for learners.
The title is the whole joke. Deletreo means "I spell it out," and that is exactly what the hook does, breaking the crudest words in the song into letters so nobody has to say them: "Suelta esa P-E-R-R-A" [Drop that btch], "Que hoy se C-H-I-C-H-A" [Cause tonight there's fck]. It is the trick adults use to talk over a kid's head, pointed at radio censors instead, and Nicky Jam delivers it in the flat, patient tone of someone reading out a phone number.
Underneath the hook is one night in Medellin that never pretends to be more than that. He sets the terms early: "Yo te trato romantic, pero no pa' ser mi novia" [I treat you romantic, but not to make you my girl]. The rest is inventory, "El VIP full de mujeres" [VIP's packed with women] and the apartment everyone ends up in: "Nos quedamos encerrao' en un PH en Poblado" [We stayed locked in a penthouse in Poblado]. Ryan Castro's half is blunter and funnier, especially his aside about her surgery: "Se dice que fue un doctor, ella dice que son los genes" [They say a doc did it, she says it's genes]. Then he drops the act, "Yo me hago el rudo, pero ya estoy desesperao'" [I act tough but I'm already desperate], which is the most honest line in the whole thing.