What has two thumbs and absolutely no idea how to proceed with this interaction?

All right, he's over the surprise. I mean this isn't outside the realms of possibility. Even though he does have a hard time picturing her actually leaving her safehouse.

He still kind of wants to hurt her for abandoning him as soon as Fontaine was killed.

Instead, he says:

"You might shoot me by accident if you've got your finger there."

What? He doesn't like getting shot.