Ninjering

Nin-Jer-Ing
Ninjering is the act of masturbating and/or wanking while in conversation with another person, but the other person does not know you've got your hand down your pants. You secretly get yourself off without them ever knowing.

Sally: "So, I was at the store the other day, buying a piece of bread...."
Dave: "Uh huh... Which store did you buy the bread at?"
Sally: "Oh, the one up the street... the one with the red roof."
Dave: "I was there the other day, was buying.. SHIT!"
Sally: "What?! What's wrong?!"
Dave: "Nothing a sock can't clean up, score one for the Ninjering skills."