I know just what you mean. It's a wonderful thing.

Jon is in a complicated place right now. He doesn't like "Stephen"; he has no experience with handling him outside of a script; and he has no idea how to improvise it gracefully. (He is also extraordinarily worried about the real Stephen, and that's making him edgy and stressed.)

Jon's ideal course of action would be to stick "Stephen" in a corner and wait for him and Stephen to switch places again. Of course, you can't do that with a living person; but it will take Jon some time to adjust.