The sexual act of defecating on your partners torso, pinching it off, and engaging in non intercourse stimulation until climax is reached, then ejaculates on the scat. Then finish the bowel movement on top of the rest of shit and cum. Forming a devil dog.
The Germans (in WWII) called the US Marines Teufelshund (Devil Dog) because they had not encountered such voracity in War Fighters from the French or English before the US entered the war. It was a designation of respect of the Marine's willingness to attack and kick ass. US Marines are called "Devil Dog" to this day to honor the past.