Depending on the dog, it may or may not be easy to teach.
It was easy for me, b/c they dogs had to learn how to nicely take a treat from my hand w/o trying to take my fingers with it (of course they aren't that nice with anyone else handing out treats, go figure
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Another thing you can try is keeping the pups on a leash while Chili is in the room. If they start acting up or bothering him, remove them from the room. Try again in a few minutes. Continue removing them every time they act up or act roughly. They (hopefully) will soon realize that if they are not nice to Chili, they have to leave.
Depending on how well they do together in a room by themselves, you may have to separate them into different rooms. That might be an even greater punishment, depending on how well bonded they are to each other.