A father sees his 4 year old son make a mess while taking a pee and
decides to teach him the right way to pee. He calls his son aside
and says, "Son, follow these steps when you go to the toilet.

1) Open your zip.
2) Pull your tool out.
3) Pull back the foreskin.
4) Pee.
5) Push the skin back.
6) Zip up your pants."

The next day, father goes near the toilet, and hears his son
following the six steps, "one, two, three, four, five, six".
Eleven years later, the father, wondering if his son still is
following the six steps goes near the toilet. He hears his son saying
"one, two, three, five, three, five, three, five, three, five, three,
five, ...., three, five, three, aaahhhhh!!!, four, five, six".