You don’t allow dogs on the sofa?!
Aww, that’s cute. We used to be those people, too. But then dog # 2 came along, and we haven’t owned the sofa, since.
Teach your Weim the “place” command that is somewhere not on the couch. A place can be a dog bed. And have the dog stay there until released. Or, crate time. Or, succumb to the fact that the couch really belongs to them, and they just let us sit on it from time to time.