Bipolaridad translates directly to "bipolarity." It's an interesting and somewhat unexpected word to find in a song, making it stand out.
In "Amor Tóxico," the artist uses this word to describe the unpredictable and extreme mood swings of a toxic partner, highlighting the emotional rollercoaster of the relationship. It's a strong way to convey the instability and difficulty experienced.
The hook is a joke that gets bleaker the longer you sit with it: "Me he vuelto alérgico / A tu amor tóxico" ("I've become allergic / To your toxic love"). It treats a relationship as a medical condition, and the verses read like the symptom list. Arguments nobody wins, so "pa' seguir discutiendo, prefiero salir perdiendo" ("to keep arguing, I prefer to lose"). Being told the whole thing was his fault. The sharpest line is "Eras el veneno en la fruta y eso te asusta" ("You were the poison in the fruit and that scares you"), which is a polite way of saying you knew exactly what you were doing.
Halfway through the anger drains out and something sadder takes over. "De tanto fuego que hubo nos quemamo'" ("From so much fire, we got burned") hands the blame to both of them, and then the song stops arguing altogether: "Todo cambió, se volvió gris / Se acabó la hora feliz" ("Everything changed, it turned gray / The happy hour is over"). The question right after it is "¿Para qué vivir así?" ("Why live like this?"), and the answer is "sin picante, sin ají" ("without spice, without chili"). Losing the heat is what ends it, not the fighting. Worth listening for the Pacific-coast Spanish ChocQuibTown keep in the writing: "ya no estamo' pa' eso" ("we're not for that anymore") drops the s sounds the way the words are actually said, and the lyrics are written down that way too.