Peeing problem, sorry if repeat, need HELP!

I have 3 questions. Please be patient as I feel it important to give background info so I can get the most informative response possible.I have 2, 6 year old INDOOR ONLY fat cats. Both male, both neutered. They have NEVER sprayed and NEVER peed anywhere inappropriately. I have not changed their littler box cleaning routine.

I caught one trying to pee on an upside down chair cushion and just about flipped out until I read the HUGE thread on peeing. Turns out my chair cushion has rubber backing on the underneath and that's the side that was facing up. #1) Is that why he tried to pee on it? Because of the rubber backing?

Recently a stray has been wandering into our backyard at night. The "boys" can see the cat as we have 2 sliding glass door and they spend their nights sticking their heads through the vertical blinds to watch the outside. Woke up last week to find that one of them (don't know who) PEED ON MY COUCH! My husband is furious and after having it professionally cleaned and sprayed Nature's Miracle all over it, it still REEKS. Also, I left a pile of towels by the washer (I do that sometimes) and today I find that they have been peed on!!! Again the washer is by a window, blinds are usually closed, no outside cats are ever seen or visible at that window. So, what the heck is going on here??? #2) Is this more likely territorial marking than a UTI? #3)Why did the towels get peed on? This is nowhere near where they saw the stray and they have NEVER peed on clothes before.

I'm not sure what to do. My hubby is mad enough that he wants to give them away. They're mine from before we got married and he's tolerating them the best he can. I don't think this is spraying. I think it's peeing.

Any suggestions? Insight?
Stef

It is possible that there is a combination of both peeing and spraying. Peeing on the towels may indicate a UTI of some sort, so I encourage you to get your kitties checked out by a vet. Cats with urinary problems often will pee on soft surfaces, and a pile of clothes or towels seems to be a common choice. You said that one of them peed on the couch. Was it on the cushion (a horizontal surface) or up the side (a vertical surface)? Spraying is usually vertical.

Regardless, a vet visit with urinalyses is in order to rule out the possibility of crystals or infections. You might also want to invest in a Feliway diffuser (though they are expensive). It might help with any territorial-ness that they are feeling toward the strays as well as helping them tolerate stress (which can lead to UTIs).

I know that there are other people here who can recommend other cleaning products to remove urine odor, but I don't have any personal experience to lend in that department.