The sexual act consisting of 2 men naked, a cup full of shit
, and a large dildo. One man shits into a cup while the other man gets into doggy-style position. The man
who has now shat in the cup sits on the other man's back, riding him like a horse while holding the cup full of shit
over the other man's mouth and nose. The man
on top also fucks the bottom guy in the ass with the large dildo, completing the "Iron Horse" This is an example of a dusty poo fetish, and can also be seen at gay orgy's.