How does Nicolás describe his childhood friend Roberto in the short-story collection, Lot?

Nicolás describes his childhood friend Roberto using an abundance of slang: “He wore his hair like the whiteboys...His fam couldn't afford regular cuts...I told him he looked like a rat, like one of the blanquitos biking all over town” (2). “Blanquito” is a vaguely derogatory (or at least dismissive) Spanish term that means “white boy.”