armarla

A colloquial, fixed idiomatic use of armar + la (referring to an unstated "gorda"/scene) meaning to cause a scene, stir up trouble, or make a big commotion — armarla is casual and almost always used exactly in this pronominal form.

• Como llegues tarde otra vez, la vas a armar. — If you're late again, you're going to cause a scene.
• La armó en la reunión al criticar al jefe delante de todos. — He caused a stir at the meeting by criticizing the boss in front of everyone.
• No la armes, mejor hablemos con calma. — Don't make a scene, let's talk it through calmly instead.

Trying to conjugate or use armarla like a regular transitive verb with a clear object — the la here doesn't refer to anything specific; it's a fixed, idiomatic chunk equivalent to "to kick up a fuss," not a normal object pronoun construction.

Often confused with armar.