So, there's actually a really funny story about this chapter, too, but I'll wait till the end to tell it.
The door to the small motel room opened and Mary walked in, holding a dripping bag of Chinese take-out. "A little help here, kiddo?" she asked as the door shut behind her and the overwhelming smell of fresh paint hit her.
"Little busy right now," Dean replied, not looking up as he flipped through pages in his father's journal.
"Just come take the food," she begged, "I need to take off my shoes."
"You could leave 'em on."
"Dean," she warned, drawing out the middle of his name, almost hissing it.
"Fine," he muttered, standing up and crossing the room to take the bag from her. Again, he tried to avoid his brother's eyes, knew for sure now what was lurking just beyond the friendly green he usually saw there.
"Thank you," she huffed, leaning down to slip off Sam's shoes. "I got some extra egg rolls. I know how much you like them."
"Thanks." Dean set the bag down on the table and picked up the journal, watching as his brother straightened up.
"What are you staring at?"
Dean smirked, his eyes traveling to the ceiling over the door. She followed his gaze, looking up, anger flashing across Sammy's face. "Dean," she hissed again, this time with genuine menace in her voice, "what is this?"
"That would be a Devil's Trap. It's used for trapping demons and rending them powerless. It makes exorcisms a hell of a lot easier. But you already knew that. After all, it's what I used to try and trap you in my car back in November."
Her anger seemed to melt away, Sam's eyes turning sympathetic. "You're confused, son-"
"Don't call me that."
"And touchy. What's wrong?"
"How stupid do you think I am?"
"Dean, just explain-"
He stepped forward, toward the Trap, journal held in his hands. "I wasn't sure at first, but this morning, after breakfast, I figured it out. It was your vocabulary. You really need a thesaurus, you know. Instead of 'weasel' and 'welch' you could try 'ditch' or 'shirk' or even 'evade.' Maybe then it wouldn't have been so obvious."
"Dean-"
"And the way you say my name. You love drawing it out, don't you, honey?"
"What are you getting at?"
He stepped up to the edge of the trap and grinned at her. "I know who you are."
"And who's that?"
"You're the bitch that stole my soul."
"You offered it up," she shrugged, Sam's eyes flashing red, "it's not my fault I made the deal. What are you gonna do about it."
"Complain, actually. You went back on your bargain."
"I did not."
"You tried to make me-"
"It's called free will, Deanster. I just planted the idea in your head. It wouldn't have been my fault if you had decided to back out."
He narrowed his eyes. "And what were you gonna do after Sam had died, huh?"
"Leave, of course. It's more fun that way."
"Well, I'm not gonna stand for it."
"What are you gonna do?" she sneered, crossing Sam's arms over his chest and shifting her weight to one foot, sticking one hip toward the wall in a clearly feminine pose that made Dean wish he had a camera.
"I'm gonna make a deal."
She snorted. "What do you have to give? I've already got your soul."
"Your freedom," he said softly, stepping away from the demon and glancing down at the journal.
"You're gonna exorcise me? Do you know what that'll do to your brother?"
"Help him? Because it sure won't kill him. The terms of our deal were pretty clear: if I tried to back out, Sam would die. I'm not backing out, I'm just sending you to Hell. That doesn't save me."
She nodded. "Smart. But you mentioned another bargain?"
Dean smirked, looking back up at the Trap he'd painted on the ceiling while she'd been out. She was powerless, couldn't hurt him, couldn't make good on her fine-print. At least, he hoped that was the case. "I won't send you back if you release me from our previous deal with no ill effects toward myself or my brother. That means no death, no backstabbing, no crossing your fingers behind your back."
"No."
He nodded and turned back to the open journal. "See you in ten months, then." He started to read.
"Wait!"
"What?"
"This deal… I don't think you understand."
"I understand perfectly. You get to continue roaming freely and making deals with idiotic saps like myself, and Sam and I go on living our lives without having to worry about suddenly dropping dead."
She smiled, a cold expression, clever, like she knew something he didn't. "You do realize," she said softly, "that if I agree to this you'll have to swap spit with your brother, right?"
"Small price to pay."
"I don't know. Years of therapy-"
"As opposed to spending a year alone in crappy motel rooms while he searches for something he'll never find? I'll take an illegal make-out session, thanks."
She shifted her weight, sticking Sam's other hip out. "Well, well. If I didn't know any better, I'd say you're gay for your brother."
"Do you want to keep doing what you're doing, or do you want to become my one-demon welcoming committee to Hell?"
"Oh, there'll be more than one."
"Answer me."
She sighed, blowing up to clear Sam's hair from his eyes. "Fine. You let me go and I'll let you live."
"Without…"
An eye roll. "Without any ill effects for you or your brother."
"Which brother?"
"You have more than one?"
"It's a possibility. Just want to be as specific as possible."
"Well," she smiled, "you're not as stupid as I thought, are you? All right. You let me go, and you'll be free from the last deal we made before the Devil's Gate was opened. As an added bonus, because I'm feeling so generous today, you and Sam won't have to worry about anybody randomly dropping dead because of this. Happy?"
"Ecstatic."
She slinked up to the edge of the trap, eyes flashing again. She licked Sam's lips and winked. "Ready?"
Dean stepped up to the boundary and nodded. The two bodies moved closer to each other and he closed his eyes. Their lips touched momentarily, just barely, and he tried to pull away, but found her grabbing the back of his head, pulling him close, determined to make the moment as cringe-worthy and uncomfortable as she could before moving on to the next poor sap who happened to be feeling especially desperate that week.
Finally, Dean was able to pull out of her strong grip and step back, his eyes snapping open, hand swiping across his mouth.
"Well," she grinned, leaning up against the wall with a smug look of satisfaction on Sam's face, "was it as good for you as it was for me?"
"You didn't have to get his tongue in there," Dean muttered, still wiping at his mouth.
"Yeah I did," she insisted. "So?"
Grudgingly, Dean grabbed a can of spray paint from its resting place on Sam's bed and sprayed a quick line over the symbol, breaking its hold on the demon.
"Thanks, sweetie," she cooed, stepping from the Trap and smiling at Dean, "see you around."
Before he had a chance to respond, Sam's mouth opened and the demon flew from the room in a cloud of black smoke. Dean barely had time to react as Sam's limp body pitched forward. Grunting, the elder brother drug his unconscious sibling to the bed and laid him down before running to the bathroom to wash his mouth out.
Funny story time! I needed a way to turn the whole Mary-possessing-Sam idea into an actual story, and Sam actually being possessed by the RED seemed awesome. I actually was really psyched about the plot twist when I went to bed the night I thought it up. The next morning, my first thought after waking up was "Oh, crap! They have to kiss!" But I figured it was a sacrifice worth making :)
That story sounded funnier when my friends were laughing at me about it.