Reventar is a powerful verb meaning "to burst" or "to explode". It's a very visual and intense word, often used to describe something breaking under pressure.
In the song, Rauw Alejandro uses it to express extreme emotional pain, singing "Ahora me revientan to' los seso'" (Now my brains are exploding). This is a dramatic metaphor for the overwhelming jealousy and frustration he feels, making it a very memorable and expressive word to learn.
This song is about seeing your ex move on, and it is not a calm, mature reaction. Rauw Alejandro kicks things off by spotting a photo of his former love with a new guy on BeReal. He notices she looks happier: "Pero con él se ve más grande tu sonrisa" (But with him your smile looks bigger). This sends him into a spiral, asking who this new person is. And his questions get intense, fast. He wants to know, "¿Quién es / El que ahora te hace el amor en el coche?" (Who is it / The one who makes love to you in the car now?) and "¿Quién fue / El cabrón que me robó tus beso'?" (Who was / The bastard who stole your kisses?). It's a storm of jealousy and heartbreak.
He can't let her go. He admits he still looks at old photos and videos of her, confessing "Hay un contenido de ti que no lo puedo borrar" (There's content of you that I can't delete). He tries to convince himself (and maybe her) that their connection was more powerful, especially physically. He argues that even if she erases his name tattooed on her, "han sido muchas sábanas mojada que son testigo'" (there have been many wet sheets that are witnesses). He even admits that while the new guy might be good for her, he was the one who "te ponía a gritar" (made you scream). But all this bravado falls apart by the end, when he's just left begging, "¿Cómo dejarte ir?" (How do I let you go?).