Castiel is rifling through the box of tapes again. Dean knows this doesn't bode well.
"Dude," he says. "What."
"Your music," Castiel says. "It's displeasing to the ear." He taps a battered tape against his palm, an uncharacteristically fidgety and human gesture. Dean gives him a sideways glance, but the case has been retaped and relabelled so many times he can't tell which it is.
"No," Dean says, "It's Led Zep, which means that it is awesome, and do not touch the deck."
Castiel gives him an insolently innocent stare and keeps his hands primly in his lap, but while Dean's head is still turned there is a click of a tape being changed anyway and Dean sighs and there is a tense beat before the music starts.
Castiel is smiling, the son of a bitch.
Dean rubs the bridge of his nose. "Okay," he says. "Look, I love Journey as much as the next guy, but I'm putting my foot down. From now on, there is a moratorium on Glee-watching for you and Sam both."
"You would do well to learn from the students of William McKinley High School," Castiel says. "Their rendition of this song is spiritually uplifting."
"Yeah, my heart is freaking swelling with divine light over here," Dean says, "and you do realize that the show is fictional, don't you," but he catches himself drumming his thumbs on the steering wheel in time with the music all the same. Irritably, he flexes his hands and clamps them back on the wheel and pointedly does not look at Castiel.
There is a moment, and then Castiel says under his breath, "It's remarkable how much the more unsavoury aspects of your character resemble those of Sue Sylvester at times."
"Dude," Dean says.