Hell's Kitchen
Sam's showing Castiel some of the most interesting books that the Bunker has to offer. Dean wandered off some time ago; Kevin went to his room and fell asleep (he'd been up all night—his body clock is shot), and so Sam and Castiel now sit at one of the tables, surrounded by books.
Off-key singing has been drifting through the Bunker's corridors for a while now, but Sam long ago learned to concentrate despite his brother's distractions. He does look up when Dean appears with three plates balanced in his arms. He's made his classic cheeseburgers with sides of fries. He sets a plate in front of Sam and one in front of Castiel on top of whatever books they were reading.
He sits down with them and watches as Castiel takes a careful bite out of his burger. He chews slowly. Then he drops the rest of the burger onto the plate and starts to violently cough. Castiel already had a glass of water in front of him and he drinks half of the contents eagerly.
"It's cos you've got inexperienced taste buds, Cas," Dean explains as Castiel blinks the moisture from his eyes. He looks at the burger on his plate as if it's personally offended him and he wishes he could smite it.
Sam eyes his own burger warily but Dean's already turned his expectant look on him so he has no choice but to take a bite. He lasts a moment longer than Castiel before he, too, is groping for his glass of water.
As Sam recovers, Dean shakes his head. "You just can't handle the spice, girls," he says with a hint of smugness, taking a bite out of his cheeseburger.
Sam has the glass of water in Dean's hand before the coughing starts.
THE END