Oh...no.

The moment Simon realized that his conquering of River's litter box was just a bit too easy and that he had unwittingly hopped right into her trap.  He should've read Bun Tzu's The Art of War more closely!

Siblings.

Sometimes their only purpose is to annoy one another.
I caught River attempting to push Simon over.  I should note that her actions were not completely unprovoked because Simon was forcibly placed in "time-out" earlier.  River is making excellent use of his distracted cleaning frenzy in order to enact her revenge.  Clearly, someone has been reading their Bun Tzu.

Simon and the un-bunny.

Simon makes first contact with the elusive un-bunny.  The un-bunny is the chief guardian of the land under the furniture.  One of the un-bunny's great talents is the ability to appear out of nowhere to guard the main pass between what is known as the couch and loveseat.  Simon is understandably wary for the un-bunny shows no weakness and holds sway over its vast dominion with an iron paw.

 Simon has been reading his Bun Tzu...a tactical retreat is sometimes the best course of action.

We have yet to figure out why Simon is so afraid of the bunny plushies, but they definitely keep him on the straight and narrow when it comes to preventing him from going somewhere we don't want him to.