My dog is 5 years old, and I just adopted a 1 month old dachshund puppy. (I'm guessing she's pure doxie, she looks it! MIGHT be a chiweenie. Maybe.)

My 5 year old, Diesel, is a bit timid of new dogs, but he's so docile and usually very submissive. He also grew up with other dogs, and LOVED them, he just wasn't socialized very well as a pup.

Now, with this new pup, my dog seems OK. He isn't her best friend, and seems kind of curious/anxious about her. When she grabs his toys, he'll growl (he does this with me too, sometimes, but he has NEVER bitten me. Ever. or anyone), and when she jumps up on the bed, he'll growl too. At first I THOUGHT this was aggression, but when she's trying to jump on the bed, he'll do a play bow, wag his tail, show his teeth, and growl. I've seen him show his teeth before with his other dog friends, whom he grew up with, when they play.

But I can't tell, and I don't want to make him stop if he's just a loud, vocal, player. And I want to keep him calm if he's being aggressive.

Thank you!

EDIT: should also add, every once in awhile, he'll try to play with her. She's so small, that I don't think he knows what to do, and stops.

EDITEDIT: The dog is almost 2 months, not just 1 month.