I love sneaky!preseries Sam testing Dean's every limit just to see if he has any, when it comes to him. And I love so un-Sam-like and so much what Dean secretly wants--because it would be; that kind of affection is so much more forbidden than the kinky shenanigans, for both of them, and exactly the kind Dean never dares think he deserves.

But my favorite bit has to be:

The corner of Dad’s mouth quirks in the rearview and Dean wants to say no, you don’t get it. If you did, you wouldn’t smile.

because when I hear Dean think it in my head, there's such a wealth of conflicting inflections there, from smug to maybe something almost grim.