[mydogrocks]

I have a 5 1/2 month GSD that has always been really friendly and generally a great dog. Lately when we go downstairs for his last pee before bed he has started growling when people approach. Also when my boyfriend and I take him on a walk he gets extremely upset if I walk away but is clam if my boyfriend walks away.
He has never acted like this before and I'm worried this could develope into a problem as he gets older

 

[mydogrocks]

He's great during the day and Ive been exposing him to as much as I can. He only has a problem at night if someone approaches me or I walk away from him, he acts totally normal and frinedly if my boyfriend walks him at night. I guess I just want to know why he has such an attitude change as well as knowing how to fix it