Two little boys go into the grocery store. One is nine, the other 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 shakes his head and replies, Nope, not for my Mom."

Cashier: "Well, they must be for your sister then?"

Nine-year old: "Nope, not for my sister either."

Cashier, curious now: "If they're 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 brother."

Surprised, the cashier asks, "Your little brother right here??"

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!"