Despistada is a fantastic adjective that means "clueless," "absent-minded," or "distracted." It's used to describe someone who isn't paying attention to what's really happening around them.
In the song, Cazzu sings directly to the new girlfriend, calling her despistada for worrying about the wrong person. She warns her, "Tienes tu enemigo durmiendo en tu cama" (You have your enemy sleeping in your bed), implying the real threat is her own boyfriend, not Cazzu.
Argentinian artist Cazzu is not here to play games. In "Con Otra," she's talking directly to her ex's new girlfriend, but it's not the usual jealous ex-girlfriend song. Instead, she's delivering a cold, hard warning. She starts by saying she has nothing to fear because she's done nothing wrong: "La que nada debe, nada teme" (She who owes nothing, fears nothing). She tells the new girl that she has no interest in getting the man back, but that karma is definitely coming.
Cazzu's main point is that the new girlfriend is worried about the wrong person. The real problem isn't Cazzu, it's the man they both dated. She delivers one of the song's best lines: "No soy tu enemiga / Tienes tu enemigo durmiendo en tu cama" (I'm not your enemy / You have your enemy sleeping in your bed). She predicts that he will cheat on the new girl, just like he did before. She says she doesn't wish her any harm, but she's sure it will happen: "Pero él te va a engañar con otra" (But he's going to cheat on you with someone else). It's a story of a cycle of infidelity where the man is the real villain.