I'm not going to give my boyfriend my homework to copy
Why wouldn't you let him copy it?
He ought to do the work by himself.
You shouldn't let him copy your work. Even if he thinks it would help him, it would be much better for him to learn on his own. Besides, he could get in trouble, and so could you.
Why can't somebody else let him copy their work?
It doesn't matter if other people do not want to let him copy, he should be doing it himself. You are not doing any favors by helping him out that way or expecting others too.