My dog lives outside but sometimes when it rains I bring him in to spend the night on the end of my bed.In the morning if someone comes into my room he will growl and snarl and show his teeth,but he never does it to me.He will only get on the bed if I say he can and he jumps of the second I say "get off".He will only act like this when I am on the bed and it is the same when we are sitting on the couch together.Why wont he let anyone near the bed or couch when I am laying on it? No one in my family has ever behaved threatening towards me but he has observed me yelling at my sister for jumping on my bed.He lets the cat on the bed and couch with us without any fuss it's just my sister and mother he bears his teeth at,but he gets along well with them in other areas.I am dominant over him,he does everything I say,and he will even stop eating from his food bowl and move out of my way if he has to.