Capillas literally translates to "chapels". It's a fascinating and clever piece of slang that you'll rarely hear elsewhere.
In the song, the artist uses capillas to refer to his flings or side girls. The metaphor suggests that while his main partner is the "cathedral", these other women are just small, temporary places of "worship". This unique wordplay reveals a lot about the artist's lifestyle and feelings, making it a very memorable term to learn.
In "ANSIEDAD", Fuerza Regida brings us straight into the messy, chaotic reality of tour life and turbulent relationships. The track kicks off with a blunt confession: "Otra vez otra en mi cama, qué puta ansiedad" ("Another woman in my bed again, what f***ing anxiety"). He is dealing with a ringing doorbell, a ringing phone, and a partner starting arguments on the other end. He uses Mexican slang like "agüite" when he says "Vieras qué agüite me da contestar" ("You should see how sad and unmotivated it makes me to answer"), showing how draining the constant conflict feels.
His defense is hilarious, bold, and terrible all at once. He tells his main girl, "Las otras capillas pa' un rato nomás" ("The other chapels are just for a little while"), pulling from the classic Mexican proverb "Teniendo catedral, ¿para qué quieres capillas?" which compares a main partner to a grand cathedral and temporary flings to side chapels. He begs her to understand the chaotic reality of fame with "Es la vida de artista / Me la navego entre loquera, desvergue de güeras" ("It's the artist life / I navigate through craziness, wild chaos with blondes"). Yet, despite all the partying, the nervous breakdown does not stop: "Y nomás la ansiedad no se va" ("And the anxiety just won't go away").