Dean figures it's just Sam throwing a tantrum when he suddenly stands up and shouts, "That's the last straw!" before grabbing his laptop and stomping out the door.
Castiel looks to Dean for an explanation. "Why is Sam upset?"
"Beats me," Dean says with a shrug. He goes back to teaching Cas how to knot his tie.
Sam’s mood doesn’t improve by dinner. He sits in a corner of the booth practicing for the Pout Olympics while Dean carefully cuts Cas’ steak for him into manageable pieces, slathering the lot with barbecue sauce because Dean’s just awesome that way.
“I’m not convinced that this is the best way to enjoy meat,” Cas says dubiously.
“Of course it is,” Dean says brightly. “Don’t you trust me?”
“Always,” Cas says.
Dean’s grin freezes when Sam decides to be a little bitch and intrudes with, “Of course Cas trusts you, Dean. After all, you brought him to that brothel and he didn’t protest at all, right?”
“Now that was a good night,” Dean says, pushing Cas’ plate towards him. “Right, Cas?”
“Yes, Dean.” Cas cautiously puts a forkful in his mouth. He doesn’t get it completely right, so Dean has to reach across and wipe the sauce from the corner of his mouth.
“What is your problem?” Dean says.
“I was just thinking,” Sam says slowly, like the start of a well-prepared speech, “That it’s such a pity that he didn’t get to go all the way that night. You’ve been introducing him to all sorts of stuff, but to miss out on sex is kind of like trying every single flavor of ice-cream except chocolate.”
Cas is getting that terrified look again, so Dean pats him on the shoulder. “Sam is right, you know. You are missing out on the best thing earthly living has to offer.”
“Yep!” Sam sits up excitedly. The glint in his eye is worrying, but Dean’s pretty sure he hasn’t been slurping demon puree lately. “I’d like to help.”
Dean makes a reluctant sound. “It’s okay, I can bring him to—”
“No, I meant that I would like to help out personally,” Sam says. He gives Dean a look. “And don’t start with the cocksucker jokes, Dean, that’s just mean.”
The words make sense but the meaning remains elusive. “What?”
“I’ll help,” Sam says, visibly warming up to the idea. “Do you trust me, Cas?”
“Yes, Sam,” Cas says, but he sounds a little reluctant, gaze moving from Sam to Dean and back like he is no closer to understanding than Dean is. “I do trust you.”
“Great!” Sam rubs his hands. “We’ll need to make a stop at a drugstore before heading back to the motel, but that shouldn’t be a problem, right, Dean?”
“Uh, no. Of course not,” Dean says through a throat that is suddenly too tight.
Dean isn’t even sure how Sam managed to convince him to join the drugstore visit, leaving Cas to wait in the car while they fetch some… supplies. Mostly Dean follows Sam in a daze, nodding or frowning whenever Sam asks for his opinion.
“Which brand’s better?” Sam asks, waving three different bottles of lube in Dean’s face. “It’s got to be something really good quality because Cas is a virgin, I don’t want to scare him off the experience altogether. What do you think?”
“Uh…” Dean points. The moment he does he gets a mental flash to lube-slicked hands running over Cas’ body, his cock, his ass. Dean doesn’t know what Cas looks like under all those layers but his brain fills the blanks easily, supplying pale skin and hard angles unused to a hunter’s life.
“What about condoms?” Sam asks. “I’m probably going to need a whole bunch.”
“What, why?” Dean asks sharply.
“Better do the job properly,” Sam says cheerfully. “Pop every single cherry he has. Oh, man, I forgot. We’re going to have to get another room. It’ll have to take all night, especially since Cas hasn’t done anything at all before… It’ll take forever to stretch him open, you know how it is.”
If Dean makes a squeaking noise, it’s only because this conversation is veering deeply into TMI, Sam territory.
Though, if the circumstances were different, Dean would not even be standing here listening to the details of his brother’s impending sex life.
Do Not Want.
The thing is, Sam is mostly a flesh-colored blur in Dean’s head. The true star is Cas, naked and writhing as he’s fucked within an inch of his life in every possible position: on his knees, on his back, in the shower, against the wall. Dean knows from experience that Cas’ll follow instructions to the letter, so there’ll be no hesitation when he opens his mouth, parts his legs, plays with his own cock.
“You okay, Dean?” Sam says. If Dean were paying attention, he’d have noticed the far-too-innocent tone of Sam’s voice. “You look a little flushed.”
“No, it’s nothing.” Dean blinks a few times, and then stares. “What is that?”
Sam twirls the oversized handkerchiefs. “Thought I might tie him up a bit. I’m not sure what he’ll be into, so I might as well try everything, right?”
Sam suddenly slides into the scenario in Dean’s head. Sam pushing Cas against the wall, Sam biting Cas’ nipples, Sam riding Cas into filthy oblivion.
“No.” Dean starts; he hadn’t realized he’d said that out loud.
“What?” Sam raises a hand to his ear. “Did you say something, Dean?”
“No, you can’t,” Dean says. “I won’t let you.”
“Won’t let me what?”
“You don’t get to sleep with Cas,” Dean says, the sudden spike of anger as sharp as it is surprising.
“Why not?” Sam asks, tilting his head in a stupid mockery of Cas’ quirk.
“I’ve known him longer,” Dean says, working up a steam. “I know him better, he knows me better. Hell, he likes me better, too.”
“So, what,” Sam says, “You want to have sex with him instead?”
Yes. Oh god, yes.
Dean doesn’t even say it out loud, but it must show on his face because Sam suddenly goes, “Hah!” and then throws the armful of supplies at Dean. “Now go do it, because if I have to sit around and watch you making cow eyes at each other for another five minutes, I am going to say yes to Lucifer and destroy the world and then you’ll be sorry!”
After paying for the stuff, they head back to the car and it occurs to Dean that he hadn’t even checked if the change of plan would be okay with Cas.
Cas steps out of the car, looking worriedly at the large plastic bag. “Is that for…?”
Dean stares at Cas.
“Dean!” Sam snaps. “Am I going to have to—”
Dean swoops in and kisses Cas. About two seconds in he starts to panic, because what was he thinking, and then Cas makes a soft, ridiculously happy sound, and starts kissing back.
“Finally,” Sam mutters, but neither Dean nor Cas hear it.