over the years i have learned that both cats and dogs will do this, they will pee on piles of clothes, like laundry, without warning, unpredictably, and as a result, i am pretty good about not leaving my clothes lying on the floor, or towels, laundry etc. I hadn't thought about my stuff being targetted if it was on the furniture, will have to keep that possibility in mind.
Once my cat peed on the bean bag chair (that i no longer have). then she peed on everything just about, definitely piles of clothes, but later i eventually figured out it was related to a bladder infection. Now that i'm thnking back, fluffy did pee on stuff that was sitting on furniture. she peed everywhere really.
Zack has peed on his own snoozy pad--he has more than once gone out of his way to go into his crate which he otherwise never goes into, to pee on his snoozy pad. It's happened a couple of times over the months. i haven't had this happen with poop with zack yet.
Once fluffy, my cat, accidentally got closed up in my bedroom one day, it was my long day when i have both my day job and my night job and don't get home til after 9:30pm. this was several years ago now. I am especially tired on those days, Thursdays, those are my once a week long days. so when i got home, brain dead, i just fell into the chair and was doing the internet or something in the living room. Fluffy can be kind of quiet sometimes so i didn't think about the fact that she wasn't around. Then, i was so tired, i drug myself upstairs to go to bed, i opened my bedroom door, fluffy ran out, and on my bed, on the sheet, because the blankets were pulled back, you guessed it, poop and pee, plenty of it, soaked through the mattress pad, and also on the blankets and quilt. i went ballistic, complaining bitterly to Fluffy while i spent a good hour cleaning up. Of course, it wasn't her fault. I just wish she could've picked anywhere else to have done it besides the middle of my bed.
The first time i ever heard of anything like this, it was 1969 and i lived in a duplex, and the people in the front, it was a couple, their names were Norm and Stephanie, and they had a pet bobcat. One time Norm had to go out of town for a few days on business. I was visiting with Stephanie and she told me that the bobcat had peed on Norm's pillow in their bed, two days in a row. She was not too happy about it. She theorized that the bobcat was angry at Norm for not being there.
you have my deepest heartfelt sympathy. I have no clue why this happend. i will say though, that when fluffy was peeing in inappropriate places, it took me 6 months of wrong hypotheses before i took her to a vet and found out she had a major bladder infection, so learn from mistake if this starts happening repeatedly and see a vet first rather than, as i did, investing in various sprays, disciplinary methods and finally, a cat psychologist. :?