Two little boys go into the grocery store.

One is nine, one
is four.

The nine year old grabs a box of tampons from the
shelf and carries it to the register for check-out.

The cashier asks "Oh, these must be for your mom, huh?"

The nine year old replies, "Nope, not for my mom."

Without thinking, the cashier responded, "Well, they must be
for your sister then?"

The nine year old responded, "Nope, not for my sister
either."

The cashier had now become curious.

"Oh. Not for your mom and
not for your sister, who are they for?"

The nine year old says "They're for my four year old little
brother."

The cashier is surprised. "Your four year old little
brother???"

The nine year old explains: "Well yeah, they say on TV if you
wear one of these you can swim or ride a bike and my little
brother can't do either."