It gets its name from the confectionary product 'Curly Whirly' and is when a male ejaculates upon a females/males arm when recieving a hand job. This is related back to the 'Curly Whirly' as there are thin strands of excess
chocolate on
the product which emulate the cum on the females/males arm. The desired effect depends on how much you 'blast out of the cannon' and the
proximity it lands over the arm of the recipiant.