I still can’t get over the fact that Cas can literally smell changes in the human body, when he’s angeled up. Like…don’t you wonder how many times he’s gotten a whiff of Dean putting off arousal smells and longing vibes simultaneously, and Cas has just had to pretend he doesn’t know what’s up (heh)? Just thinking about him coming out from cleaning up after purgatory, and Dean’s awkward boner shiftiness when he laid eyes on Cas, and how Cas’ smile just looked so pleased at Dean’s reaction.
But on the other side, how many times he’s squinted at random not-Dean people when they’ve hit on him, and I’m just imagining him thinking “Ewww, you don’t smell like Dean. Please stop with your longing and horny B.O.”