Mixed messages if dog's allowed on one couch but not the other?

The answer is: It depends.

It depends on how simply and/or quickly you'd like to train your dog. The simplest way to keep the dog off your living room couch is to enforce an "off all couches" rule in the entire house. You'd also do yourself a favor by enforcing an "off all chairs and beds" rule as well.

I believe that most dogs have the capacity to understand the difference between the den couch and the living room couch, however. Therefore you can train your dog to stay off one and not necessarily the other; it's just a matter of enforcing the "off the couch" rule in one room and not in the other. I think the additional time and energy involved in teaching this has to do with the fact that most dogs will try to see what they can get away with by testing you for longer than they would if the rule applied to all couches in the house. This is where we humans often fail: In the ability to stick wtih a rule or a training regimen for more than 1-2 weeks.

So, if you decide to allow one but not the other, be prepared for a little pushing of the limits to find out where the limits actually are. Stay firm, keep consistent, and make sure everyone in the household is as well. And be ready for your dog to "not get it" for longer than if you kept him off all furniture.

Once you decide which option you're going to take, training will involve your consistent supervision of his proximity to upholstered furniture in order to enforce the rules. It may also involve teaching your dog a reliable "Off" so that you can enforce verbally and not physically. You could even go so far as to set up a video camera in each room to remotely spy on your dog.

In the meantime, provide your dog with his own nice comfy bed--maybe one in each room. Not only will he be happier but you'll lose most of whatever guilt you may be feeling over whatever policy you're going with.