As any of you with kids know, it can be difficult to interrupt the playtime of a three-year-old for anything as trivial as going to the bathroom. My son loves imagining he's Thomas the Train and as he was playing I asked him to go to the bathroom. He was dancing the subtle dance.
He responded, "But I'm a train and I don't have a penis or a butt so I don't need to use the toilet."
I'd love to say he gained an extra five minutes of play for his wit. However, he "choo-choo'd" his heiny to the toilet as I barely contained my laughter.