Knife masturbation is obviously - masturbating with a knife. A form of knifeplay which involves fucking yourself with a knife, could be several different places. I prefer my asshole. The hard part is sticking the tip inside. Or if there is rigid ends it becomes more difficult. Some may enjoy poking themselves with knives but youll never truly live until the blade is up your ass.
by Giant ballsack Tumor May 13, 2016