[His Majesty may get upset with him, but Josak has been all over this place since his arrival--and more than once. Yuuri's reckless behavior would just get in the way.
And working with Vash is just not an option he'll consider unless he has no others left.]
I'll be fine, just keep an eye on His Majesty.
[He's a spy after all, these kind of situations are what he's good at. Hopefully leaving Yuuri in Vash's care won't be a choice he comes to regret.]