Mom:  (points to end of couch)  Lie with your head here.  

Ethan:  Why does it matter?

Mom:  I dont want your feet over there.

Ethan:  Man, there’re a lot of rules at this hotel…

Mom:  And don’t fart on my couch, either.

Ethan:  What could a fart do?  It can’t stay in the couch forever.

Mom:  It could, if its potent enough.  Dad’s done it.