No Bullies Allowed
First of all you must let the bully know that what he/she is doing is not acceptable. They are not in charge of this family you are. A good place to start is by using The Nothing In Life Is Free training program click this link:
Nothing in Life is Free Gaining control of your dog humanely
If the bully sleeps with you, that is not allowed right now. Sleeping with the PLP* is earned by good behavior, not a right. (the PLP means Provider, Leader, Protector or Parent, Leader, Provider) This is really important when dealing with aggression, guarding behavior, and urine marking.
Watch your bully carefully for signs of pending aggression. Interrupt the behavior with cue word(s) that you use every time. We use 'ENOUGH' which means stop what ever you are doing right now. You can choose what ever feels natural like 'No Way !', 'Stop IT !', you can clap or stomp to emphasize the cue word. If the dog stops and looks at you, call them and praise, example, Good Boy Sammy, and pet. When you can supervize, I also recommend letting the bully drag around a leash attached to their harness, this gives you something to grab if necessary. Having a leash hooked to their harness reminds them that you are the PLP, not them. I hope this helps. I have other retraining lessons if you need more suggestions, just let me know. Hugs Teresa