Okay, still digesting the finale, but there is one parallel I think needs drawn:
Dean tells Cas he is important to him and Sam because he’s their brother. Which on the face of it is fantastic, really. We know Dean puts Sam above all else, so calling anyone else his brother, not “like a brother” but actually “brother” is essentially the highest compliment he can pay.
I see how some people might interpret the Cas and Dean in the car scene as a ‘no-homo’ moment. And honestly, that might be what Dabb and company intended.
However, thematically coupled with what comes later…
Amara says the reason she was drawn to Dean is because she misses her brother and was using Dean as a substitute. Flat out, we’re told that The Mark = her bond with her brother.
So…why the fuck was she kissing Dean, then? If it’s supposedly a sibling bond they shared?
Easy, she felt drawn to those who possessed the mark because they represented love. More specifically, spoiled love and confused love. God loved her and his creation both. He would not give up one for the other, so he did the only thing he could do: he separated them. He didn’t lock Amara away because he hated her, he did it because he loved her. He could have done far worse than giving her the solitude she supposedly craved; she is nothingness, she destroyed because her default is nothingness, can anyone really blame Chuck for his attempt to grant her isolation?
Amara does not understand how she could love anyone other than her brother–she doesn’t understand how to love anything other than her brother and emptiness until the very end of season 11. So, being drawn emotionally to anything that is not God or nothingness is inherently confusing for her.
And she doesn’t know how to express those feelings. Truthfully, she only kissed Dean after she tried to eat him (and not in a sexual way). She wanted to be near him, but did not know what that meant, so she expressed it in a way her vessel (a human woman) prompted her to.
So, why is this important in understanding Dean and Cas’ impala scene?
Amara mistakenly expressed her love for her brother in a romantic/sexual way.
Dean in turn mistakenly expressed his love for Cas in a fraternal way.
These two scenes are set up in such a way that I can’t help but thematically compare them, whether the parallel is intentional or not.
So, in conclusion… Cas is clearly in love with Dean (God, his face at the end of that conversation, I mean, sheesh), and Dean doesn’t yet understand the true nature of his feelings toward Cas.