Necio translates to "stubborn", "foolish", or "obstinate". It's a powerful word that goes beyond simply being wrong; it implies a stubborn refusal to see reason.
In this bachata classic, Romeo Santos uses necio—the song's title—to describe his state of mind. He knows it's irrational to pursue a woman who is already taken, but his overwhelming feelings make him act like a necio, a fool in love who won't give up.
Romeo Santos teams up with guitar legend Santana for a bachata track that is completely obsessed. The title word, necio, literally means foolish, stubborn, or persistently annoying—and Romeo owns up to every bit of it. He is pursuing someone who is already taken ("tienes dueño" [you have an owner / a partner]), fully aware that he is crossing lines. He even blames a little devil sitting on his shoulder ("en mi hombro hay un diablito que me agobia" [on my shoulder there is a little devil that overwhelms me]) for tempting him to send late-night calls and flowers, flat-out refusing to settle for the friend zone ("no se me ocurra aceptarte ni un segundo como amiga" [it doesn't occur to me to accept you for a single second as a friend]).
The lyrics lean heavily into madness and delusion. Romeo describes himself pacing the streets like a reckless stalker and talking to empty reflections ("un loco hablando con reflejos que no están" [a crazy man talking to reflections that aren't there]). Calling her his "fruta prohibida" [forbidden fruit], he compares his uncontrollable infatuation to jumping headfirst into deep water: "Mi amor alucinante se lanzó al océano por terco / Y me estoy hundiendo" [My hallucinatory love threw itself into the ocean out of stubbornness / And I am drowning]. It is dramatic, slightly unhinged, and driven by Santana's fiery rock licks right alongside classic bachata rhythm.