Yeah I have a similar story...

This happened right after me and my wife moved into a new apartment. Our dog's bed is at the foot of our bed. Apparently I woke up in the middle of the night and just started peeing on the little guy. My wife said she woke up because he started going crazy trying to make me stop. She asked me what I was doing and I just replied "We always do this," as if it was normal. She knew something was up so she asked me what my middle name was and I said "Thomas (true)...Or Montana." Montana was where I was born.

At this point she's freaking out at the whole situation and starts taking the sheets off our bed since my pee had gotten all over the bottom of them as well. She tells me to go let our dog outside because he's still freaking out so I do. We go back in and I just laid down in the bed and went back to sleep. I woke up 20 minutes or so later after she had given him a quick bath and thrown everything in the laundry. I remember asking her why she was doing laundry in the middle of the night and she told me everything.

The funniest part of the story is that the next day, we both left for a while and when we had gotten home, our dog had peed on my pillow. Never in his life had he done that and he's never done it since. I can't help but feel like he was getting back at me...

I've had several other incidents but after looking it up, it seems like there's several things that cause it. Genetics, new places, drinking, and stress are some of them. My dad has had a history of sleepwalking his entire life. As I mentioned, we had just moved to a new apartment. We had had some wine to end the night after a long night of unpacking. And our cat had found the tiniest hole next to the dishwasher and had been lost the entire day which caused us both a lot of stress looking for her. It was the perfect storm.