Sometimes, Castiel will think of the body of James Novak as himself and that scares him.
He would be midthought and think "my body" and have to correct himself. This was James' body, whether James' soul was still in there or not. It was never his body, not really.
Sometimes he wonders if these are really his emotions or if they're remnants of James' humanism. As Castiel stares up at Dean, cheeks flushed, he wonders if his heart (no, James' heart) was skipping beats because of the things James would feel if he was still around or if this was something entirely unique. He wonders if this is really the sensation James gets when touching Dean Winchester or if this is something new.
Dean Winchester ties James' stomach in knots when he looks at him. Do these knots belong to this vessel or to Castiel himself?
Castiel loves all things. It is God's way. He was born loving all things, but for some reason, he loves Dean Winchester more than all things. He wonders if this is what humanity is, if somehow this vessel is influencing these thoughts. He remembers how some angels would lay with humans, but he never saw a reason to or even felt that desire before meeting Dean Winchester in the body of James Novak.
Is this the vessel talking or is this Castiel? The fingers he flexes, are they his fingers or James'? He is forgetting where he begins and ends in this vessel. He wonders if Dean sees only James Novak and not the angel inside. When he thinks of Castiel, what does he think of?
Why do the thoughts of a single human matter so much?
He decides to talk to Sam about these doubts, since he knows Dean's responses would be evasive and angry.
"Am I still an angel?"
Sam laughs and says yes, but Castiel is serious. He no longer feels like he belongs anywhere but inside this vessel. His home was heaven, but more and more, he thinks it's inside James, and more than that, he thinks it's beside the Winchesters.
He corners Dean after a night at the bar. Sam is still in the library, doing research for the latest hunt. Dean's eyes show bewilderment as Castiel presses a hand over Dean's heart.
"Am I really touching you right now or is this just James?"
Dean tries to shrug him off, but Castiel pursues him to the other side of the room. Dean's response is typical: "Dude, you sound like a chick."
In his natural state, he is neither male nor female. James is a man. Castiel is now a man.
Castiel shows up at a restaurant where Dean is finishing his pie. Dean only briefly glances at him, cheeks flushed. Sam stares at him inquisitively.
"Do I ever hurt or is this only this vessel's pain? Guns shouldn't be able to cause angels pain."
He reveals a wound that causes them to rush back to the hotel. Sam runs out to the store when all of the bandages are used. Dean sits in silence across from Castiel.
"Angels don't breathe. We don't need to."
"That's nice, Cas."
Castiel huffs. He wants Dean to really listen to him this time, not just blow him off. "Why am I breathing right now? Is it my breath or the breath James requires?"
Dean finally looks Castiel in the eyes, and Castiel takes in a sharp breath at what he sees in them. Dean closes the gap between them and Castiel all but trembles as Dean brushes his lips over his own.
"Now, tell me. Was that you I kissed, or Jimmy?"