Labia is a fantastic slang word for "smooth talk," "the gift of the gab," or a special kind of silver-tongued charm used to persuade or seduce someone.
In "200 COPAS," KAROL G describes a manipulative ex who has "una labia... digna de recuperarte" (a smooth-talk... worthy of winning you back). It perfectly captures the ex's ability to use charming words to cover up his bad behavior.
Learning labia is great because it's a single, memorable term for a person who always knows just what to say to get what they want.
This song is the ultimate pep talk from a friend who is absolutely fed up with seeing you cry over a worthless guy. KAROL G sings directly to her amiga (friend), telling her to stop pretending she's okay. She's seen her friend bite her lip to be strong—"Se muerde los labios pa' poder ser fuerte"—and she's asking how much more crying it will take to see he isn't worth it.
KAROL G's solution is simple and direct: "Amiga, deja solo a ese payaso" [Friend, leave that clown alone]. She lays out a plan for the night which involves drinking all "doscientas copas que hayan en la barra" [two hundred cups at the bar] and singing her other famous song, "Tusa," until the bar closes. Her main goal is to get her friend to finally believe and repeat the phrase, "el pedazo de mierda es él y no soy yo" [the piece of sh*t is him and not me]. It's a blunt, loyal, and powerful anthem for anyone who needs a friend to drag them out of a bad relationship.