A/N: This is written for SPNAdventCalendar2020, day 1 on tumblr by bend-me-shape-me. Prompt: Advent Calendar.

"Ah, there we go."

Dean finished with what he'd been doing, and now he stepped back, arms crossed to survey it. He'd taped an Advent Calendar to one of the walls in the war room, using far too much duct tape because the nothing had wanted to stick the cardboard to the stubborn ass stone.

Castiel walked in at that moment, carrying a large roll of wrapping paper.

"What are we looking at?" he asked, placing it down and leaning it against a wall.

Then, he stood beside Dean.

"What's that?"

Going up to it and tapping it, he explained, "This is an Advent Calendar."

"Advent. As in the season in the liturgical year of Christianity focused on waiting for the Nativity of Christ, and his Second Coming?"

Dean raised his eyebrows. "Who the hell took you to Sunday school?"

Castiel just tilted his head at him, his lips in a thin line, as if to say, I'm an angel, you dumbass. Right. Right, that he was.

Dean went back to the Advent Calendar to try explaining, and then a question came to mind. He turned, finger raised. "Also, is Christ even real?"

"As in being a part of God?"

"Yeah, sure."

"Jesus was a real person. He was a carpenter, born in the Spring, and he was crucified. I wasn't watching humanity at that time, so it's hard to say if the Christian religions are correct on all their points about him."

"Thanks, 'cause that clears it all up."

Castiel didn't catch his sarcasm, and gave a small smile. "You're welcome."

Then, he went up to Dean, slipping an arm about his waist. Dean leaned into him, their hips touching, the sides of their bodies nearly flush against each other. Castiel kissed him near the top of his head.

"So explain," he demanded.

"You see this little flap right here?" Dean asked, gesturing to it.

"I do have eyes."

Damn, who spit in his cereal today? Though, the sarcasm was starting to make Dean tingle inside, heat pooling down, down, to in between his legs. Breathing normally became a struggle, and he didn't try to hide it. Cas just twisted slightly, hips pressing against him, as if he could sense Dean's mood.

"So—so, the little flap is something we open on each day of Advent, and then…" Dean opened the first one seeing as it was the first of December, and a square piece of chocolate fell into his hand. "Ta-da!" he announced, showing it to Cas. "Want it?"

"It'll just taste like carbon, oxygen, and hydrogen to me," he explained.

"Right. Uh… does that—does that taste good?"

Castiel started laughing at that, took the chocolate from Dean, and then pressed it into Dean's waiting mouth.

"Mmph!"

He started chewing the chocolate, letting the soothing, rich taste flood his tongue. Castiel didn't remove his hand, and his fingers ran over his lips. Dean nearly shuddered at it, and his toes curled in his boots.

"I think I like Advent," Castiel said.

"Why?"

"Because I'll get to feed you chocolate every day."

Dean started laughing, and pulled Cas into him, his own hips pushing against his.

"You're such a sap. Come here."

They kissed, and Castiel slipped his tongue into Dean's mouth. He probably tasted carbon, oxygen, hydrogen, but he surely tasted more. Dean didn't have time to wonder what his mouth tasted like to an angel, because Castiel was soon pressing him up against the wall. Dean pulled away and smiled at him. His angel returned it, eyes bright with happiness.