Maybe - cats can be like that. Whilst Guinness lives with us, he has also claimed both Peter's and Godfrey's boats as his own (although I am glad to say that he was content with just wandering in, rather than feeling the need to spray).

One excellent way to punish a cat - you know the spray bottles for misting plants? Set it to open so it ejects a solid stream of water and shoot it at the cat. It wont do any lasting damage (except to his pride), but it is one thing that they seem to remember.