I have four cats, 2 males and 2 females. One of the males is 6 months old and repeatedly pees on my bed most nights. He has no problems going to the litter tray through the day and some nights though. I have four litter trays spotted throughout the house, and none of the other cats go anywhere else. The cleanliness of the litter trays has no effect on whether or not he goes on the bed, as sometimes he does it when all the litter trays are clean.
He used to pee on the carpet in different corners of the house, but this behaviour has now stopped. He only does it when we are sleeping, and it makes for a very unpleasant alarm clock! All the cats sleep on the bed at night (if it takes their fancy) but he is quite possessive of me, if another cat gets close to my head or wants attention he will block my face from them, although he has no problem with them getting attention.
Also, I don't know if this is important, but my other male (the kitten's dad) was neutered about 3 months ago, which has stopped most of his tomcat behaviours, but neither of my 2 females are spayed (mum and sister), although neither have been in heat (the last time mum was in heat was when he was one week old, and even then it was only for a day). He is not neutered yet. I also have a female dog who is currently in heat, but despite this these factors seem to have no effect on this behaviour.
6 months old is prime time for hormones. Sounds a lot like marking and territorial behavior. Especially since daddy isn't "top kitty hormonally speaking" anymore. Sounds like neutering may be a good choice in his near future. This may help curve his need to exhibit this behavior. Good luck.
The Content on this Site is presented in a summary fashion, and is intended to be used for educational and entertainment purposes only. It is not intended to be and should not be interpreted as medical advice or a diagnosis of any health or fitness problem, condition or disease; or a recommendation for a specific test, doctor, care provider, procedure, treatment plan, product, or course of action. Med Help International, Inc. is not a medical or healthcare provider and your use of this Site does not create a doctor / patient relationship. We disclaim all responsibility for the professional qualifications and licensing of, and services provided by, any physician or other health providers posting on or otherwise referred to on this Site and/or any Third Party Site. Never disregard the medical advice of your physician or health professional, or delay in seeking such advice, because of something you read on this Site. We offer this Site AS IS and without any warranties. By using this Site you agree to the following Terms and Conditions. If you think you may have a medical emergency, call your physician or 911 immediately.