Wow Jen, that is a tough one. Poor Codie bear. He is so sweet, I hate that he's being bullied. Though Maybe it doesn't hurt him, or maybe it feels like a grooming or something. Not sure. I know this sounds kind of weird but what if you rubbed some deodorant on his fur, not enough to get to his scalp, since he's kind of fuzzy. But just enough that when Cali tries to lick, to get to chewing then she won't like the taste
That is the only other option other than seperation, that I could think of. I wouldn't want to use the deodorant spray or bitter apple, cause that might irritate his scalp, but jsut reg. deo stick, rub it in your hands and just gloss over his coat and see what happens. Poor baby give him auntie kisses for me.