This is the title of the song and literally translates to "barbed wire". It's a striking phrase that you wouldn't expect to find in a love song, making it instantly intriguing.
Bad Bunny uses it as a powerful metaphor, singing "Me amarraste el corazón con alambre de púas" (You tied up my heart with barbed wire). This vivid imagery perfectly captures the feeling of being trapped in a painful yet inescapable love, making it a very memorable and poetic line.
In this song, Bad Bunny is completely obsessed with someone. He says she's so special that when she gets in his car, she makes it look like a Mercedes-Benz. He's not interested in anyone else, telling her, "Tú eres la baby, no te cambio por cien" (You're the baby, I wouldn't trade you for a hundred). His desire is both sweet and super intense. He wants to kiss a specific beauty mark she has, and he gets straight to the point with lines like, "Si me dejas, te hago un bebé" (If you let me, I'll get you pregnant).
But it's not all happy. He seems to be remembering a past moment, regretting that their last time together was the last time. The feeling is so strong and painful that he says, "Me amarraste el corazón con alambre de púas" (You tied up my heart with barbed wire). This isn't a gentle kind of love; it's something he can't escape. He even calls her a witch, "tú eres bruja", because the hold she has on him feels like a powerful spell.