We have it too in The Netherlands "wildplassen", since the Dutch "wild" (as in "in the wild") can indeed also be translated as "wild" (as in uncontrolled), the standard response when caught is "No officer, I was, in fact, peeing very calmly."
I've heard a few English parents tell their children to take a "wild wee".
The Dutch even have educational public service survival guides, and canal side bars will lend you a free pisriem or piemelpijp to prevent accidental death.