This is my first puppy/dog (although I've trained my sister's dog) of my own. He's nine months old now and is an intact Pit/lab mix.
Lately he's started up a new "game."
My puppy has been having fun messing around with my sister's dog (chi/jack/dach). Anyways, Fritz (the little dog) will be chilling and chewing on a toy. Fen (my puppy) sees him and just HAS to mess with him. He'll try to take the toy and Fritz will growl and give him full warning to back the heck off. So of course Fen keeps hopping around (often in a play bow) and causes Fritz to growl more and more. Fen will then paw at him (often to try and take the toy) or just try and knock Fritz around by nudging him with his snout. This often sets Fritz off who then charges at Fen. Fritz then barks and snaps but Fen just avoids it and moves like it's a game. Fritz will go back to the toy and Fen will do it all over again.
Fritz makes it painfully obvious that he doesn't want to be messed with but Fen doesn't care. I've scolded Fen when he does this but he'll just jump back a few feet and start messing with Fritz again a few seconds later. If I get up to make him back off he'll take off and try and get me to chase him (play bow and excited barking as well sometimes).
He's started this within these last two months so I think it's some adolescent dog-game or something. However, Fritz's barking gets REALLY annoying and I fear Fen might never learn to respect other dogs (at least smaller dogs, he's gotten himself bitten by screwing around with older and larger dogs).
So, is this normal annoying puppy behavior or should I at least keep a close eye on it?