Peeing.. at wits end

My cats hate me... I have two female cats (sisters) just under a year old. Before we moved we never had a problem, as we were fostering the entire litter of cats, they were kept in a room (mom and 6 kittens) with two litter boxes and only given the run of the house under supervision. Once we only had our two left, they were given run of the house but put away at night (I didn't trust my dog not to play them to death). Since our move in February we've had pee problems. It started right after the move, they didn't like the location of their litter box and peed on the carpet in my office instead. I caved, moved the litter box and the problem seemed solved. More recently (a couple of weeks now) I have come across evidence of them peeing in the oddest places. Counter tops, the couch, and most recently my office chair. And its always on my stuff! I live with my boyfriend, and they haven't peed on any of his stuff. But they've peed on my sweaters, my hat, my overnight bag, and now my office chair. I really don't know what to make of it. It just doesn't sound like your typical 'peeing on the carpet because they don't like their litter box' or even peeing in a basket of fresh clothes. Its only ever on clothes that smells like me (been worn) or things that only I use (chair and bag). Ideas?! I've been treating the areas with enzyme cleaner and putting things in the wash, but reoffending (due to smell residue) isn't the problem. They always pick something new. And I can't even tell if only one of them is doing it, or both. Please, any and all suggestions or even an explanation would be more than welcome. I just can't live like this!

Moving causes cats to stress, and stress can cause urinary infections, which can cause cats to pee outside of the litter box.

First question: Have the cats been to a vet to rule out a medical cause for the improper urination?

I highly doubt that's it, though of course I'm really not sure what the symptoms would be. They both just seem really content, healthy appetite and so on. But I'll bring them in just to be sure. Any other ideas?

I don't know if this is important, but they are indoor/outdoor cats and use their litter box for feces just fine. They also pee in it when they're locked indoors, just apparently not always