The answer's in the question.

(I present a true-life nanny story. I will henceforth refer to my charge as "the kid" to keep from embarrassing anyone.)

*The kids and I are sitting at a table playing Attack Uno.*
Kid: “Can I ask a question?”
Me: “Sure man, shoot. We don’t stand on ceremony here.”
*Kid looks at me in confusion. I sigh.*
Me: “Ask away bud.”
Kid: “Would it be OK if I went to the bathroom right now?”
*The game slides to a halt with everyone staring at the kid.*
Me: “OK, before I answer that let me just repeat what you just asked so we can be sure that I heard you right. You are asking me whether it’s OK if you pee your pants right now?”
*Kid half-nods.*
Me: “OK first let me just say that no, it is most certainly not OK for you to pee your pants; and second, intentional pant-wetting is just wrong on so many levels.”
Kid: “Well, I am wet anyway.”
Me: “Right, the crucial difference being that right now it's water not urine.... in fact why don’t you go put on some completely dry cloths before we play anymore.”
*Kid walks to his room to get his clothes.*