Cat issues???

We got a new puppy about a month ago. Him and the cat play and romp around alot. The cat acts all mad when the puppy comes up and starts playing, and gets all growly and hissy, but I know that if he didn't really like the puppy playing with him he would jump up on the couch or somewhere the puppy can't reach. He lays outside the crate when we have the puppy in there and plays with the puppy through the bars. That's not the issue though. Ever since we got the puppy, the cat has been pooping on the couch or on the stairs(carpeted). He's been housebroken since we got him a year ago, and the only other time he pooped outside his litterbox was when we switched litter on him. We switched back to the old litter, and he was fine. Is he pooping on the couch because he's jealous of the puppy? Anyone know what his problem is? My fiance is about to kick him out and make him live outside.