Last night I told my gsd to get off the bed and he barked one short very loud bark then jumped off the bed only to jump right back on it. Once again I said no. Off. He jumped off layed somewhat on his side and curled his lip up at me, but didn't growl. He was a fairly obedient dog until I had him altered, but it could be I'm letting family stay at the house which has turned the house into a chaotic ever going mess. I am trying to think of a possible reason in the sudden change or maybe i was oblivious to the subtle signs.I want to correct this behavior before it turns out badly, but am not positive on the approach I should take with him. I have never had a dog do that before so I'm caught off gaurd. Do you think it could be the amount of people staying at the house? He does fine in large crowds and listens to me when I tell him to sit. He allows strangers to pet him with no apparent sign of nervousness or aggression. He is possessive over his toys when it comes to sharing with another dog, but not towards people.He doesn't behave aggressively towards dogs outside of the house. He does not growl or snarl at dogs in the house either. He just steals his toy back if the other dog has it or if I'm trying to pet the dog he butts in pushing himself between the other dog and anyone petting the other dog and not him. I don't let that fly, but he still attempts to do it regardless.