Tepache (teh-PAH-cheh) is a fermented beverage made with pineapple. Although it has a very low alcohol content it was very popular in Mexico in the good old days. The expression regar el tepache means to "spill the tepache". Once spilled, any fluid can hardly be recovered from the ground. This powerful analogy illustrates that some things once done, cannot be undone. That's the case with secrets. Once the word is out, there's no way to restore the secret. Regar el tepache means to spread the word that was supposed to be kept secret.
Hijo: ¿Qué esta haciendo la tira en la casa, papá?
Papá: Tu tío regó el tepache y las autoridades se enteraron de que tenemos un criadero clandestino de víboras de cascabel.
Son: What are the cops doing in our house, dad?
Dad: Your uncle couldn't keep the secret and the authorities learnt that we have a clandestine rattle snake farm.
Tepache is sold in street markets in Mexico City. If you find it, try it.