[On one hand he does like that David is helping. He definitely needs it. But in another way, he doesn't want those extra eyes on anything underhanded he may be planning... So he's a bit torn on the response - regardless of which way it went.]

How am I your responsibility? I appreciate that you want to help, David. I truly do. But you're not my guardian. You could never talk to me again and it wouldn't be any real concern of yours what happens next. You're blameless. Nobody is demanding you keep an eye on me.