Any tips for me with a puppy and one of my husky dogs?

Kind of long winded:
I have one Husky Shepherd mix(9) and a Rescue Husky (he’s 6 but have had him for 3 years ). I just brought a 17 week old Husky shepherd in 2 days ago and it is going great indoors/ outdoors with the 9 year old, but the other guy is only good outside with her, unless she tries to drink face to face out of a puddle with him. other than that he pretty much ignores her. The first night after we introduced them outside (all was fine). we came in on leashes and he started to jump and howl/growl. he is normally super chill and just hangs by himself in the bed room then randomly comes out to play or he hears the cheese wrapper rustle lolol. I have a gate up right now so he can’t come down but can see, but also he’s not trying to come out unless he does hear the wrapper of course. basically he’s not trying to bust out and get at her. and he is no longer jumping and screaming/ growling. he now just kind of bares his teeth and looks calm. i do know that he wants her away when she does that. she also doesn’t try to like get at him either, just kinda puppy stomping around near him.

I am going to continue working with them outside as well as inside but just looking for some tips if anyone has any!