The chaotic instance in which, during urination (esp. females) in a public area, the wind whistles through your legs, blowing your pee way off course. Can either end up in front of you, or covering your dropped jeans, resulting in a wet and smelly situation.
I experienced pee and blow the other day when I was crouching down by the roadside... my jeans got soaked. My mom had to put a towel on the car seat.