I agree also with the comment about socializing, My Morty was rescued from a hoarder house and I believe he was just not socialized right as a kitten and that is why he is aggressive. He is very affectionate, but very agressive too.
About your boyfriend's frustrations, my mom had a cat Puffy when she was dating my dad and when ever he even came near the cat she would throw the biggest hissy fit. Her tail would get big and her hair would stand up growling, swatting, and hissing. They never figured out why. Guess it was just in her nature. And my dad is a great guy so it wasn't her sensing a bad vibe. I guess if she is not seeking out to torture him, he should just pursue a relationship on her terms. It'll be okay.
About your boyfriend's frustrations, my mom had a cat Puffy when she was dating my dad and when ever he even came near the cat she would throw the biggest hissy fit. Her tail would get big and her hair would stand up growling, swatting, and hissing. They never figured out why. Guess it was just in her nature. And my dad is a great guy so it wasn't her sensing a bad vibe. I guess if she is not seeking out to torture him, he should just pursue a relationship on her terms. It'll be okay.