Now tell me Cas/Dean isn't canon
SEASON 4
Ep 10: Heaven and Hell
Dean Where's your boss?
Uriel: He's not here. See, he has this weakness - he likes you
Episode 15: Death Takes a Holiday
Castiel: To everything there is a season
Dean: You made an exception for me
Castiel: You're different.
Episode 16: On the Head of a Pin
Dean: Since when does Uriel put a leash on you?
Castiel: My superiors have begun to question my sympathies
Dean: Your sympathies?
Castiel: I was getting too close to the humans in my charge - you. They feel I have begun to express emotions, the doorways to doubt. This can impair my judgement.
Castiel: For what its worth, I would give anything not to have you do this.
SEASON 5
Episode 2
Castiel: I killed two angels this week. Those are my brothers. I'm hunted, I rebelled, and I did it - all of it - for you. And you failed.
Episode 14
Dean (on the phone): Cas. It's Dean. Yeah, room 31c, basement level, St James Medical Centre.
Cas (standing in front of Dean, on the phone): I'm there now.
Dean: Yeah I get that.
Cas: I'm gonna hang up now"
Dean: Right
Episode 18: Point of no return
Castiel: May be they're desperate. May be they wrongly assumed Dean would be brave enough to withstand them.
Dean: You know what, blow me Cas.
Dean: Woah Cas, not for nothing but the last person that looked at me like that - I got laid.
Castiel: I rebelled for this? So you could surrender to them? I gave everything for you and this is what you give to me?
OFFICIAL TIE-IN NOVELS
War of the Sons by Rebecca Dessertine and David Reed
Page 41 - " 'He's [Castiel's] our friend, but he's still an angel. He hasn't always been honest with us before'. Sam knew that was hard for his brother to hear - Dean had been growing closer and closer to Cass since the angel had rebelled against heaven."
Page 322 (Cas, answering his phone) - "Dean, your absence has been...concerning me"
Page 325 - "Sam and Dean recounted their journey to Castiel over burgers. Sam noticed that Dean left out a lot of details, most of them concerning Julia".
(Dean had slept with Julia, a fellow hunter, and had started to get emotionally involved before returning. Why would he specifically try to avoid telling Cass about it?)
Even some of the writers ship them!
Ep 10: Heaven and Hell
Dean Where's your boss?
Uriel: He's not here. See, he has this weakness - he likes you
Episode 15: Death Takes a Holiday
Castiel: To everything there is a season
Dean: You made an exception for me
Castiel: You're different.
Episode 16: On the Head of a Pin
Dean: Since when does Uriel put a leash on you?
Castiel: My superiors have begun to question my sympathies
Dean: Your sympathies?
Castiel: I was getting too close to the humans in my charge - you. They feel I have begun to express emotions, the doorways to doubt. This can impair my judgement.
Castiel: For what its worth, I would give anything not to have you do this.
SEASON 5
Episode 2
Castiel: I killed two angels this week. Those are my brothers. I'm hunted, I rebelled, and I did it - all of it - for you. And you failed.
Episode 14
Dean (on the phone): Cas. It's Dean. Yeah, room 31c, basement level, St James Medical Centre.
Cas (standing in front of Dean, on the phone): I'm there now.
Dean: Yeah I get that.
Cas: I'm gonna hang up now"
Dean: Right
Episode 18: Point of no return
Castiel: May be they're desperate. May be they wrongly assumed Dean would be brave enough to withstand them.
Dean: You know what, blow me Cas.
Dean: Woah Cas, not for nothing but the last person that looked at me like that - I got laid.
Castiel: I rebelled for this? So you could surrender to them? I gave everything for you and this is what you give to me?
OFFICIAL TIE-IN NOVELS
War of the Sons by Rebecca Dessertine and David Reed
Page 41 - " 'He's [Castiel's] our friend, but he's still an angel. He hasn't always been honest with us before'. Sam knew that was hard for his brother to hear - Dean had been growing closer and closer to Cass since the angel had rebelled against heaven."
Page 322 (Cas, answering his phone) - "Dean, your absence has been...concerning me"
Page 325 - "Sam and Dean recounted their journey to Castiel over burgers. Sam noticed that Dean left out a lot of details, most of them concerning Julia".
(Dean had slept with Julia, a fellow hunter, and had started to get emotionally involved before returning. Why would he specifically try to avoid telling Cass about it?)
Even some of the writers ship them!