More soap please

A few mornings ago, Max came out of the bathroom and said "Hey, the pee is still on my hand."

So I told him to go wash his hands again, and he did.

A while later he said "MOM! The pee is still on my hand!"

I told him to go wash his hands again, and he did.

This happened several more times during the day and each time I told him to wash his hands, and he did.

After washing his hands multiple times, Max came out of the bathroom, rather distressed. "I keep washing my hand and the pee still won't come off!"

Then he held up his hand to show me the letter "P" his teacher stamped on the back of his hand at preschool the day before.