While performing Heterosexual coitus in what's commonly known as the "The doggy style" position at the top of a staircase with both participants facing the stairs.

As one or both reaches climax, the male party knocks out the arms of the female, causing the fall forward onto her stomach. the male then rides the woman down the staircase like a sled. Also Known as: "Improvised Bobsled" and the "German Anyhow"

Variations include "The angry Dragon" this is when the female participant is a Redhead.