Cornish Rex now having BM out of litter box

Question
I have a Cornish Rex, about 16 months old, whom I've had since
age 4 months from a reputable breeder.  I have half-time
custody of our three children - twins age 11, son age 13 - they
spend 3-1/2 days week here.  The cat is affectionate, seems to
get along with all (best with me).  The kids occassionally tease
the cat mildly (nothing cruel; hold the cat, often they want the
cat to sleep with them, and they chase after him and grab him at
night; the cat almost always - by his choice - sleeps on my bed
and on me or between my legs).  No apparent change in the
interactions between thekidsandthe cat.   The cat just started
pooping on the bed of the 13 year old.  His bed is on the bottom
floor, just outside the room where the litter box is. His bed is in
a large finished room in  the basement, which is also where I
have my desk and home-office.   The litter box is well-kept, and
had been used well and regularly.  It's an electronic one - the
kind that cleans itself - I've had it for about a year, no problems.  
No changei n type of cat litter.  The cat urinates in the box, and I
think he's still pooping in the box when he doesn't go on the
bed.  The cat is a neutered male.  No other animals in  the home.  
The cat NEVER leaves the apartment. The cat is affectionate and
playful, but has been acting a bit "jumpy" or odd the last 10 days
or so, and has pooped on the bed 6 or 7 times.  Obviously, I
wash the sheets or whatever is soiled ASAP.  I even saw him do it
once, in the morning, only me and the cat at home, kids at
school.  First, he was sniffing and pawing - I picked him up, put
him in the litter box.  He didn't poop. A few minutes later, he
was back on the bed, and then he pooped.  I saw him do it; I ran
over but was too late to stop him.  I let him know my displeasure
and put him right into the litter box.  The cat doesn't act sick, no
change in food nor eating patterns.  The kids haven't acted any
different to the cat to account for the cat's new behavior.  I'm
tired of cleaning poop and washing sheets.  Do we have to play
cat psychiatrist or is there some product I can use to keep the
cat from the bed? Or would  

Answer
Hi Dean,
Sorry to hear of your dilemma.  I can understand your frustration with this.  There are, indeed, products that help deter animals from specific areas.  One is Boundary, a not-so-offensive-odor for us, but cats detest it! No Go is another brand.  Check with your local pet shop.  I used to use it around the tree during the holidays to help train the cats to stay out of it.  But, before I would try a deterent, I think I would make an appointment with the vet, just to rule out any health issues.  For example, cats will tend to urinate outside a litterbox because the urinary tract infection discomfort they feel, is associated with the box and not the act of urinating.  Consequently they will go to other areas in search of 'relief' from the discomfort.  I'm not sure that this type of thing is happening from the perspective of a colon problem, or if he just has 'issues' with the 13 year old in the house.  It is said that cats can be rather 'vindictive' for lack of a better word.  That would seem to be the case in some of the behaviours supporting that theory.  But I'm not so sure, and if  I were, I'm not sure I would know what to do, either, not having taken any classes in kitty psychology!  However, there ARE those who are 'cat behaviour specialists'.  I am not sure if there are any on this volunteer site, but perhaps you could check with a vet or pet shop or grooming shop, to see if they know anyone in the area that could give you better information with matters concerning undesirable behaviour.  
Good luck with this, and hope you get some helpful information!
Thank you for your inquiry,
Tomay