Oh and just be careful how rough you play with him, especially if that encourages nipping...
I find my dog plays as rough or as gentle as I do - and given I really don't want her chomping on me - no matter how excited - I always play gentle. And I freeze up the second she's a bit too rough.
Anything that's cute as a puppy might not be so cute when he's done growing - tho I'm going to take a huge stab in the dark and say - he's probably not going to get a lot bigger.
He is a dog and a terrier - don't ever let him play with the pet budgie or mouse. Or even within reach. And he can still murder your favourite (dirty) undies.
"I'm a girl" - I completely guessed that wrong - based on your username - oops.