Yep been there too!! My Piper was once upset with me because she couldn't go outside because it was raining and rather than go in her litter box she got up on the couch looked me square in the eye and squated!!
I still swear she did this on purpose to get for not letting her out to run around but I couldn't get mad because she got and came and licked my toes!! Crazy girl!!!! It's worse in the bed I hated having to get up and change the sheets - but this too shall pass!!