Someone who is very skilled at wanking covertly in the same room as another person - the master of risky wanking. The Wank Ninja can successfully wank in a number of locations without being detected: in the back of the car with their family, under the table during a meeting, on the sofa next to a friend, etc. The art of the silent finish is vital, as is suppressing any hint of the Orgasm Face.
The other night, my girlfriend totally managed to get herself off three times during dinner with my grandparents - she's such a wank ninja.
by TheWN March 04, 2012