Liliana,
I know what you mean (anyways I did not post this thread) and I get upset when my dog Mackenzie sleeps on the couch and an idea is to maybe cover her bed with her own scent and either cover the couch with a scent that doesn't bother you but bothers her. I think both of our dogs are a little crazy but maybe if the scent thing doesn't work than if you don't mind you could maybe cover the couch with plastic. But that's just a thought.

Hope something works
Devon