look up any word, like bukkake:
An activity in which many High-School aged males participate, where the purpose of the "game" is to give a firm, backhanded slam on another males genitals in order to cause him discomfort. Also referred to as balltapping.
I gave Ricky a powerful and accurate wangtap and he cried like a 6 year old girl.
by TellyfromKids June 24, 2005
Origin of "wang tap Wednesday"

To get hit in the nutsack
That was a classic wang tap
by Kopit February 20, 2013