My dog peed on my roommate's son's bed

[MiaRose100907]

Hello-
I have posted on this forum before regarding my German Shep/Pit Bull mix. He is a 4 year old, fixed male. Today, while I was at work my roommate text me and told me that my dog peed on his son's bed.
Is there any reason WHY he would do this? He is super good about telling us he needs to go potty, and has never done anything like this in the past... plus it seems like an odd place for him to go pee if he DID have to go and my roommate was just not paying attention (which, I wouldn't be surprised if happened).
I told my roommate that he needs to take the dogs potty once while I'm at work. Apparently, he's been waiting until about 2:30pm to take them potty everday I'm gone. I leave for work at 5am and that is usually the time I take them potty, right before I leave; so today they held it for almost 10 hours. He told me that he hadn't taken them yet today, which could explain why he peed in the house but why the bed? Why not on the floor by the front door? Could he be marking the bed? My roommate mentioned that he could have smelled his sons pee from the accident he had on the bed a while back and could be marking over it.
Any insight would be wonderful!
Thanks everyone!

Oh, and don't worry, I told my roommate that he cannot wait that long to take them out. He needs to take them out earlier than 9 hours later from the time I took them.

[OnceInAWeil]

How much pee was there? If it was a lot, he probably was not marking. If it just seemed like a few drops, or a small dribble, the marking is a possibility (although even if it was a lot, smelling the urine on the bed could have confused him).

Your roommate definitely needs to take them out sooner, as you've requested. Also maybe shut the doors to the bedrooms if possible. If he has another accident, get him checked out at the vet. He could have a UTI or something else.

[Nettle]

If the bed already smells of pee, it is highly likely why a dog bursting for a pee would think it was a good place.

Often it's a security issue, but I don't think so in this case.

[emmabeth]

Oh yep, bed smells of pee, and will smell strongly of 'boy' also, thats GOT to be a good place to pee for a dog who is busting to go and also has learned that he DOESNT go on floors/carpets etc.. it makes total sense and your housemate is a doofus for not realising dogs might need to pee sooner than 10 hours!

[MiaRose100907]

Yes, I agree my roommate needs to learn a few things about dogs. I've had to teach him quite a few things I've noticed him doing as far as training goes, but taking them potty sooner is #1 on my list.
He says he will do it and take them out sooner, so hopefully he will hold to that.

And, the pee spot was rather large, so I'm assuming that it was probably a combo of needing to pee and wanting to mark. I felt bad for my boy having to hold it that long

Thanks everyone for the advice. I figured that was the issue, but I like to ask anyways cause you never know if you might have overlooked something that someone else will notice

[Nettle]

Perhaps put a note on the cistern that says HAVE YOU TAKEN THE DOG OUT? to remind roommate that 10 hours without a pee is more than they could manage either.