The rusty piston Share definition Flag The result of having rough anal sex, and your shaft is covered in feces and blood, giving it that rusty color. I ran into my ex last night, and the rusty piston was on my bucket list. The rusty piston by Jmc1971 CM75 September 3, 2018 0 0 Get merch Get the The rusty piston mug. Buy Now — $32.95 See more merch