[YorkieMother]

I be very upset if that was my dog.

Six hours or so in your room nice and safe is not to long.
What about a baby gate and divide the apartment in two down a hall if possible one side for Alfie and the rest for the big dogs.
Alfie should not be a rude puppies play toy even if it a puppy it does not have great manners and it not Alfies job to teach it.
If you roommate does not understand the risk to a 4 pound yorkie then maybe a move is needed.
We have one rule in our house well two no yelling at the dog or in its area but this one is...No other dogs come in contact with mine ever without me there and oking it ever. There is no taking it back if something happens and well there no living with me if it does.

JL.