I have a lot of reading to do this semester and my favorite place to read is sitting on the downstairs couch. The light is best there and it's pretty comfortable, but more importantly my dog and cat often join me, one on each side of the couch.
Today while I was eating lunch the dog got up on the cat's side of the couch. We have a towel there for the cat to sit on and the dog decided to sit on the towel. It wasn't a problem until I sat down to finish my reading for class today. As usual, the cat came over to sit on the couch with me—and she noticed the dog in her "spot." Twice she jumped up on her usual side and kept finding the dog there. So she tried to find another spot—the other side of the couch, the top—eventually settling on the arm for a little while, where she sometimes sits. In the meantime the dog stretched herself over my lap, making it very difficult to read. (Of course I didn't move her; she was all settled and snuggled in, after all.)
Thankfully the dog and cat have had some experience living in close quarters together and neither is too fazed anymore when the other one gets too close. When we moved from California to North Carolina they spent five-and-a-half days together in my car: The dog stayed in her seatbelt in the back and the cat roamed around. (The cat used to travel between Oregon and California with me so she's an old hand at long car rides.) I think the uniqueness of that event changed their dynamic; the dog still teases the cat once in a while but not nearly as much as she used to. (Age may have something to do with that, too, since they're both older now, but I'm gonna stick with the drive-across-the-country theory myself.)
I'm happy to report that today's couch story does have a happy ending for the cat. Eventually the dog got tired of balancing on my lap and rolled off the couch to go lie on the floor. (I think she heard a squirrel outside, too; she had to go to the window to check it out.) As soon as the dog left the cat promptly came over (seriously, it took less than a minute), settled in her spot on the towel, purred and went to sleep while I finished my reading. My cat's world had been restored.