A device that is attachable to vaginas, and measure the amount of dick that the vagina gets. The measurement is in d/m (Dicks per minute). It is a very useful device and can be used for many purposes such as:
a. It helps keep track of how big a slut you truly are
b. Gurls can have dick offs/
competition where there will be an
objective judge
c. Proving your fat friend Janet, who claims she gets loads of D, is a
fucking virgin