They will get the message and realise that if they sit on the floor they still get fuss and treats. We then progressed to one on our laps with the other on the floor at our feet and both getting treats, the both up and getting lots of praise and treats. They are only allowed up with our permission as Jakey location guards so we can't have him jumping on our furniture when he wants because he won't let us on
We do still have grumbles and growls but the guilty party gets put straight back on the floor.
Don't know what to say about the barking all night though because we had a nightmare with Jakey, needless to say that both dogs sleep in our bedroom on their own beds
It was either that or all the neighbours complaining.
Itakes patience. Meg has found it hard sharing us with another dog but we're getting there. It is worth it though. I also read "The Culture Clash" by Jean Donaldson and that helped.
Good luck
Louise x