Sometimes I could strangle them! (Not literally, please don't send the SPCA to my house.)

We moved into a new house a few weeks ago and one of them started peeing on the carpet in the basement. Now, we think they both are in a literal pissing contest to see who "owns" that patch of carpet.

We woke up today to another wet spot even though their litter boxes (plural) were just cleaned last night.

Now, I get to spend my sunny afternoon in the basement running the carpet cleaner.

How do I get them to stop?!