Dog Urinating on Owner's and His Bed?

I am having a problem with my 8 year old mini Yorkie urinating for the first time on my and my boyfriend's bed. We first thought it was our sausage dog. Then tonight he came through with me to the kitchen to get something and walked straight passed his potty pad onto his bed and urinated and walked back through to the kitchen.

The other dog and his bed wasn't there, but I wasn't even putting him in there. He has never done this before, but they both had been in trouble for urinating on the bed. We have been building for a long time so I don't know if it's because of that stress?

Please help.