you don't have the balls....
A woman is driving down the highway. The highway was originally in New York, but in the retellings I read both took place in Pennsylvania. The woman notices a police car behind her with his lights on and she starts to get nervous, planning what she will say when the officer pulls her over. The officer appoaches her vehicle and before he demands her license and registration, she chimes in, "I know! You pulled me over to invite me to the policeman's ball!"
To which he replies, "I'm a Massachusetts state trooper, ma'am. We don't have balls."
Upon realizing what he has said, he clears his throat, tips his hat and walks back to his car.