A Rotten Cotez is a combination of the Dirty Sanchez and the Strawberry Shortcake. First you insert your finger/penis into her ass, after building up a coating of feces, you wipe it on her upper lip. After this, you ejaculate on her face, aiming for the eyes, then punch her in the nose. The resulting spanish mustache is responsible for half the name, also the blood shed symbolizes the struggle for the fountain of youth and the jizz "tears" the sorrow of never finding it.
That slut from the club was so drunk, she didn't even press charges after I gave her a Rotten Cortez.