How do we deal with this? He’s a sprocker and definitely in full-on adolescent mode. He sleeps in his bed in our room at night. The other night he decided he wanted to be on the bed. DH told him to go to his bed and he ignored him, so DH went to lift him off and he showed teeth - just for a second. DH told him to go and he did. Then yesterday he was trying to get to the cat who was on the table so DS got his collar to move him and he physically put his mouth round DS’ other arm. Not a bite, just held it - DS stood still and dog stopped. I stress that I do not think the dog is aggressive, just that he is testing boundaries due to his age. We handle him in a positive way with treats etc (eg he goes in his crate for a biscuit when needed so is happy to go in) but obviously I don’t want him thinking this is acceptable behaviour as an adult dog. Any advice?