Welcome to owning a GSD puppy haha.
The thing that always worked for us is "the fun stops" when there is bad behavior. When the puppy jumps I say "off" and turn/back away and don't engage. If we are playing with him and he mouths, then it's "no bite" and fun time stops for a min. Warden loves to lay on the couch with me but sometimes gets too excited being at my eye level and tackles me/mouths etc and I just say off and walk away for a few mins! We've always had success with this, but it takes time!
Sent from Petguide.com Free App