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''
Cashier- ``Well they must be for your sister then?''
Nine year old- ``nope, not for my sister either.''
Cashier curious now- ``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 of them!''