He can't answer that because last time he was asked that, by someone who could have actually given him what he wanted, she made a promise that was either a lie to begin with or just not worth keeping in light of how inconvenient she found him! And before that, he had what he wanted and he was specifically disallowed from keeping it!

Now he knows better: asking him what he wants is just a means of denying him exactly that.

So, ask him again.