Our indoor cat is fairly tolerant. The litter box can be down right foul and she still uses it. Last night my pillow was marked by the cat. This morning the dog bed was marked by the cat. A pair clean pants was marked by the cat. And now, the couch marked by the cat. Perhaps she was expressing her discontent that someone had thrown trash into her litter box.
Today I learned that I can punt a 30 yard field goal and have the football land on its feet. Perhaps I was expressing my discontent over an expression of discontent.