A Kangaroo Pouch Surprise is when you clasp your penis in one hand while the other hand is in the shape of the middle finger gesture. The middle finger pushes down on the
head of the penis, causing it to go inside the penile
shaft, forming a baggy of
skin. Very quickly the middle finger hand pinches off the
skin, creating a "kangaroo like pouch". You then proceed to urinate, thus filling up the pouch. When you release your fingers, the urine filled pouch bursts everywhere creating a "surprise" of urine.