[Yes, we're walking. Itachi seems unbothered by that reaction, content to drag along a willing participant (however one defines willing) in his pursuit to escape the shore and its nosy natives. Once they've begun to move, he does adjust to match the pace of the other man, even if it requires slowing somewhat.]

... It isn't a matter of trust. [Well. Partially untrue, but there's a more logical reason.] Blood loss is a weakening state, one I cannot risk.

[He has a genetic illness which has led him to quite a lot of blood loss in the past, so... he needs all he can get. Though Itachi has felt fine in this shared dream thus far, he can't assure that will last.]

Tell me more of the conditions of your vampirism. What was the transition like? How long did it take?