Vasodomy is the act of a bald man, upon placing butter (margarine will suffice if you're health conscious) onto his scalp, using his lubed up head to anally penetrate another person. Some believe that the term arose from the little known Norwegian god Va, who was the god of baldness and sexual prowess.
Vasodomy is not necessarily the reserve of men, some women, Gail Porter for example, have the tools for the job.
It has been suggested that the true aim of Vasodomy is for the victim (the vasodomised) to be penetrated so hard by the attacker (the vasodomiser) that he has no choice but to cough up his own testicles.
'I don't know what it is about sitting in Church but I always get antsy for some Vasodomy.'