I live in a two (modified to three with a wall) bedroom apartment with two other girls my age, my dog Ryuk, pretty much a school of fish at this point, an old cat, a millipede, and a lizard....
My dog and the cat have a tolerant relationship, the cat has no fear of dogs (having raised two very large puppies himself in his younger days), and when Ryuk gets to annoying the cat ready and willing to knock him down a couple of pegs (also helps that this is a very lean and muscular cat that tips the scale at about 18lbs). For obvious reason Ryuk doesn't get to play with the fish, he knows to stay away from the millipede tank or risk a good inking in the face and that the lizard area is in cat territory, and should be avoided at all costs....the issue is the flatmates, or rather ONE of the flatmates....
One of my flatmates (we'll call her "J") grew up in the woods around dogs, she knows nothing about training (I've met her childhood dogs, no proper training but good manners, both are respectful dogs) but she gives off this "you don't mess with me" sort of vibe about her. Ryuk respects her and will listen to her for the basic things (out, go lay down, sit, wait, stay, here etc) when it's important and will respect her wishes when she has company over by staying out of the way, etc....the problem is with the other one, we'll call her "S"
The only dog "S" has ever lived with was her aunts elderly lab and that was only for a few weeks years ago. She gives commands like timid questions or optional requests and naturally my pup treats them like they're just that...optional. No surprise, this causes some issues when I'm not around and she will not keep the dog in his crate when she's home and I'm not, she's 100% convinced it's cruel and nothing I've said or shown her will convince her otherwise....
We have people over all the time (we're college students...we occasionally behave as college students lol). Usually these are close friends in groups no more than seven. When I'm home my puppy is put in his "place" (which is a doggy bed under one of our coffee tables) after greeting everybody (he goes to the door to let us know someone is there, once we say it's okay he backs off into the living room and sits there until the guest comes in and greets him), given a bully stick, and just will hang out, sometimes doing cute tricks for popcorn (I know, I know, human food is bad >_>

I've made sure he knows he's allowed to hang out with us as long as he's a good boy, and the moment he begins to get a little to excited he's brought into my room (where it's quiet), given something to chew on, and crated away from the action to calm down. If the party does get a bit out of control he will also be crated up (this has only happened once due to a crasher and I ended up letting him out on lead to bark at this guy and get him to leave...amazing what a strong bark can imply)
Now we did and experiment once after I was told how my usually well behaved puppy acted when I was not around during a party....
"S" took him out back on leash, I came home through the front door and hid in my room. They came home, settled in, invited some people over. The guests come in and Ryuk is weaving around their feet, jumping up, getting in the way, begging, and "S" my flatmate is doing her quiet questioning "off?" commands. He was in mid jump when I walked out, I didn't have to say a word, ears dropped, tail dropped, he was in his place with a toy immediately. He knows what he's supposed to do, and knows that he wasn't doing that. Now I know it may be a little to much to expect that reaction out of him when "S" walks in the room but I would really like him to at least register he heard her.
I did teach her about a week ago to give "not-optional" commands which she's been doing quite well on, and I've tried to include her in training sessions. The problem is while I'm around, he's focused on me, only me. At first I tried telling her what commands to give him but he listened to me rather than her. So we moved to flashcards I would hold up, and she would read the card as a command so he would hear only her....it took him two days to figure out the flashcards. I guess since they all look different he attached a command to the shape or a way I held the card? Whatever it was, he would face me and would do whatever was on the card...so that stopped working. Then we moved to making a list on the wall with commands she called out in random order, after each one he'd check for my approval before carrying them out, if I didn't move or look at him he'd come up to my feet and sit, waiting. If I left the room he'd either shut down or ignore her. I've tried having her hold the tastiest of treats, with me holding nothing, I've tried her feeding him (he does sit and wait for his meals when she feeds as he does with me), when it comes right down to it, she's still lower ranking than he is...
I should also note he is also NEVER aggressive towards her, but rather treats her like a little puppy to be cared for. If she stubs her toe and makes any noise he'll go to make sure she's alright, he'll sleep under her desk when I'm not around. He'll bring her food in bed (this one has been...intersting) She knows not to take away a toy he's chewing on or anything so we've never had issues there but he has no problems if she picks up the toys he's not using (all the bones in the house are technically "mine" anyway, I only let him borrow them). I don't let him play tug with her but he will play with her, and drop toys into her hand. It's just in our house the hierarchy goes me, "J" , cat, small pets that spray dogs with yucky stuff if they come near, small pets in cat's domain, Dog, and "S"...
is there anything I can do about this?