Nervous urinating

Question
My dog is an 8yr old mini doxie, and I have had him for about 10 months. I have no idea what his hx is, but other than this nervous peeing he does, he has been great. A common scenario would be him laying on the bed, and then someone needs to sit down, so they scoot him over and he pees. If you look at him or say anything, even in a gentle tone, he pees more. So I wind up walking out of the room until he is ready to come out since I don't know how to approach him, and I feel so bad. I think he may have been mistreated in his past. He is so shy.

Answer
I suggest obedience training. Obedience trained dogs know better what is expected of them and so are more confident. Of course I suggest positive dog training using only positive reinforcement. You may find a trainer near you at http://www.betterdog.com or do a search in a search engine.

Once you've got the basics of how to train your dog a command, you can, for example, train him to move instead of being scooted when someone needs to sit down, so the scenerio you described will look more like:
"Doxie, excuse me" (in a gentle, conversational tone) dog hops down and looks up expectantly for a treat or a pat. Person sits down, dog gets a scratch, everyone is happy.

Your trainer may have to do some work to help him overcome his shyness so that he can be trained, but I find a little bit of baked liver makes short work of that bit.