Who's always poopin' in the halls.

The story:

Not I, but my younger cousin who, in his Kindergarten class when called upon to sing a song he knew, gleefully belted out, "Who's always poopin' in the halls?!" Thus was a guileless, naive young nun scandalized.

Later the nun told my aunt, whose habitually mischiveous (ADD? - we didn't have that in those days!) son had committed the lyrical sin; and my aunt told everyone so that the incident has since become a fond, endlessly amusing family legend.