Cat peeing issues.

Alright, here's the scoop. Pun intended.
We've had our cats for about two years now, we adopted them from a shelter, and they are both about two years old. We moved back in April and there were no problems with adjusting, then about a month ago we noticed pee on the bed. Cleaned it, so on and so forth, and took them to the vet to get checked. The male had some urinary issues (they were minor) and we were diligent with his medication.
We just got back from our honeymoon, and everything was fine, except there was now pee on the couch.
My wife's dad kept an eye on them while they were gone, so they had food and water and were scooped everyday, so can I assume this instance was because of our absense? A little rebelling, if you will?

We went on another trip a two Xmases ago, and didn't have these problems.
Is this just a case of kitty being ticked off, whereas the other instances were related to the urinary issues?

I am getting to my wits end here.

I think they both need to go to the vet with a pee sample. Most of the time when cats have accidents, it's because they're sick. If one or both of them have had urinary problems in the past, it might be that again. I buy a premium food that says it helps prevent UTI's and that seemed to work after the initial UTI was cleared up.

Congrats on the wedding!

I'd also like to mention, UTIs can be a recurring problem. Even though you treated once, they could have a UTI again. I suggest another vet visit to rule out a UTI. Then once a UTI is ruled out, you can look at behavior modification.