I have had this problem with my cat, Luna. She's female and was 7 months when it started, getting spayed did not help. She's doing it to show me that she disagree with things, for example when I'm coming home late or that she thinks her litter boxes have to be cleaned (I had to set up a second litter box and I have to clean them twice a day; by peeing on my bed, she taught me that she wants it that way).

What I try to say is that - when there is no medical reason for this - a cat often choses this behavior to tell us that he/she is not happy with a situation. We "only" have to find out what it is and then try to avoid the problem if possible.

However, apart from this, my vet also recommended to use a spray called "Feliway", made of synthetic facial pheromones of the cat, the pheromone P3 to be exact. Since a cat associates a comfortable place with that scent or its "nest area", it won't pee there. I've tried that, and it worked.

Kirsten