What is British Clapper?
1.
The act of shaking or flapping a man's genitals until they make a clapping noise. Usually done in groups to see how loud of a clap one can get, also for bragging rights. Only done in groups after calling the requisite, "No homo."
Yo dude, Scott is the loudest British Clapper!
I know man, I wish I could clap that loud!