Friend gets mad when I won't tell him what happens in the Potter books?

Question:

Friend gets mad when I won't tell him what happens in the Potter books?

but He won't read them, yet he keep throwing us theories of what he thinks will happen based on what he's seen in the movies.

So, what should I do? I don't want to spoil the books for him, but he really gets mad when his wife and I smile when he inquires on his own theories (and usually they're wrong), and that we won't tell him. Note: He is 33, and I am 21.

Additional Details

5 days ago
I've told him to read the books but he's one of those people who has trouble reading. I've also offered the option of the audio books, but he still gets mad because his wife and I are rereading the books (this will by like my 8th time) and he knows that both of us know them inside and out.

5 days ago
And now he's acting like a child by not speaking to me, or his wife, and going out for hours at a time...which is highly unusual for him.

Best Answer - Chosen by Asker: 5 days ago
I've told him to read the books but he's one of those people who has trouble reading. I've also offered the option of the audio books, but he still gets mad because his wife and I are rereading the books (this will by like my 8th time) and he knows that both of us know them inside and out.