Do not disturb

Sam and Elena each got new notepads today, and were eager to put them to use. One of the first things Sam did was to - in typical boy fashion - make this sign for his door.

In response, Elena made her own sign. Fitting to the "girl stereotype," hers included a more detailed explanation as well as an exception clause in case she should change her mind. (I'll write out what it says underneath in case you can't read it)

"NO BOYS
 P.S. If you do you will be sorry!
 P.S.S. You can come in only if I say so."