When the female partner empties a gallon of milk inside her asshole, the male partner then lays directly below the woman's anus and opens his mouth as wide as possible to receive a huge load of poop/milk diarrhea into the his mouth, having the appearance of chocolate milk or mud.
friend 1: Daniel you finished all the milk!?!?
friend 2: Yeah man last night my chola gave a full serving of a Peruvian mud cup:)
friend 1: Nice!!