Mear pa'rriba

Mear pa'rriba literally means "to urinate aiming up." In Mexican slang, this expression means "to behave in a way that is harmful to oneself." In other words, when you meas pa'rriba you ruin your immediate future with your own actions. The parabola is a powerful parable. 

Example:

José: Acabo de ir a recursos humanos a proponer una estructura más horizontal para que aumente la participación en la toma de decisiones y se limiten el poder y los abusos del jefe. Quedé muy satisfecho.
Feliciano: Nunca había visto a un soberano pendejo tan contentote después de haber meado pa'rriba. ¡Pinche animal!

Jose: I just came back from HR. I proposed a more horizontal structure to increase the participation in decision making, and to put limits on the boss' power and abuses. I'm pretty happy about it.
Feliciano: I never saw such an oblivious dunce, so happy after having harakiri-ed his career. ¡Poor moron!