As a NZ Policeman walked to her car window, flipping open his ticket book, she said, 'I bet you are going to sell me a ticket to the Policemen's Ball.'
Spoiler:
He replied, 'New Zealand Policemen don't have balls.'
There was a moment of silence while she just smiled, and he realized what he'd just said. He closed his book, got back in his patrol car and left.