Jensen Ackles, Sweetheart,
If Dean only looked at Cas as a brother from your pov, then all those intense looks and chemistry must mean SOMETHING so you might have some issues to look into here about yourself.
Bcoz 12 years of brotherly bond isn't how it played out. Misha admitted it he said he was in denial. You said you didn't. And it's okay your opinion it is. But...
Dean wasn't looking at Cas in the brotherly way he looked at Sam. And we all know it even you.
That's the tea. Jensen.