You walked into the bunker when you heard the sound of clicking joysticks and virtual gunshots.
"No.. No! No!" you heard Dean growl. "Bitch!" he then shouted to his little brother who was sat next to him on the couch. Sam laughed at his own victory and replied with the usual "Jerk!"
It made you happy when you saw the two brothers having a good time with each other. You stood around the corner, listening to their silly talks and fights when it suddenly went silent after a while.
"You can come in and play with us" you heard Dean say. You hadn't noticed you giggled out loud at their 'bitch-jerk' fight. "..or you can stay there, whatever" you smiled and walked around the corner to show yourself. Sam looked confused and slid his right foot beneath his bum.
"How long have you been in there?" he asked. You blushed and explained you just got back from shopping. "I'll leave you two alone then" he said after a while and left the room. You walked up to the spot on the couch where Sam had been, and kissed Dean on the cheek. You and Dean have been dating for two months now and to your amazement it still went as smooth as you'd hoped.
"Hey" he said as his eyes lit up.
"Hey" you replied, pulling your knees up to your chest and leaning onto your boyfriend.
"How was shopping? Bought anything nice for yourself?" he wondered and put his arm around you.
"I did!" You got up and walked back to your bag around the corner. "Shoes!" you grinned and held them up so he could see them. Dean looked somewhat puzzled at the shoes, he didn't really know if he liked them or not. "At least Crowley thought they were nice on me.." you said, putting the shoes back.
"Crowley?" Dean sat straight up after hearing the name roll off your tongue.
"Yeah.. He popped up in the store when I tried them on. He then said they were looking good on me" you replied and smiled awkwardly, making sure he knew you didn't go in detail with Crowley. You walked back to the couch, but Dean was still looking at you with a frown as heavy as his pocket knife. As usual Dean was very protective over you and got jealous easily. You haven't even sat down yet or he'd started mumbling on again.
"Why would he randomly follow you to a store?" he replied and shrugged. "Cause I will put him on a leash again if he doesn't watch his ass" Dean said as he looked away and pouted. You threw your head back in laughter because of the expression he made while he said something ridiculous like that. "I mean it!" he stated once again, and looked back at you. He couldn't keep a straight face either and laughed with you.

[…]

After a short but sweet afternoon spent with your boyfriend, it was time to go home. You stepped out of the Men of Letters bunker, but as soon as you stepped off the entrance path, Crowley had appeared behind you.
"So, I've succeeded in making the boyfriend jealous.." you heard Crowley say behind you. Your heart skipped a beat in distress and you turned around. He'd put up his grin again and said "You don't mind, now do you?" He tilted his head a bit while waiting for your answer. You sighed and walked on. "Oh come on! Don't deny it!" he shouted. You rolled your eyes but ignored him anyhow. After a while you looked over your shoulder to look if you were still being followed, but Crowley was long gone. Crowley loved playing god, that's what you figured out in the past couple of weeks.

[…]

You turned the key in the lock of your apartment while you searched for Dean's number in your phone. You put the phone on your ear and kicked the door shut, waiting for Dean to answer his phone.
"This is Dean's other, other cell, so you must know what to do" You heard on the other side. "Damned, Dean!" you shouted as you threw your phone aside. "No, I don't" you sighed out loud, thoughts pondering in your head. It's not that urgent anyway. 'It can wait,' you thought. You stood up and walked over to the fridge when your phone went off. You picked up and heard Dean's rough voice on the other side. You explained what just happened outside the bunker and listened what Dean had to say about it.
"That's it," he said, followed by the abundant sound of clanking chains exceeding his voice. "You, get back here right now" he continued.
"Wait, what are you going to do?" you asked in confusion.
"I'm gonna gank his ass" he replied before the connection broke.

[…]

Several minutes later you made your way to the bunker, and to your surprise, Castiel opened up. You looked up in confusion as you didn't know why he was there as well.
"You must be wondering," he said, "I've been told I'm here to protect you-" he paused and looked around to make sure you were alone. "While.. Dean is ganking Crowley's ass" he continued as his face got more serious with every word. Castiel tried to act as if he knew what he was talking about. He frowned in misunderstanding when you tried to keep in your laughter. He sensed something and tilted his head. His eyes widened and asked "I said that right, didn't I," as if he committed a crime. You patted Cas on the shoulder and walked inside. You finally found Dean in the dungeon of the bunker, attaching chains and shackles to a chair on top of a devil's trap.
"Don't be too harsh on him," you said as you walked in. "He's kind of human now so he kind of.. feels things.."
"That's exactly what I'm aiming for" he replied, watching over the installation as a proud father.
"I mean, he can feel things he hasn't felt" you said, "Like, I never saw a demon having feelings for something or someone" you continued, defending Crowley's position.
"Doesn't matter, we have an excuse now" he said and gave you his puppy smile. "I guess we'll wait for Sam before we summon and kill him"
"True.." you sighed. "Where's Cas?" you asked, wondering if the angel had followed you inside. Dean was confused and asked "What do you mean? Cas was never even here?" You were confused now as well.
"Yeah, he was.. He let me in" you said. Dean looked concerned now and ran to the library. You ran with him, back to the entrance where you had met Cas a couple of minutes ago.
"That wasn't Cas," you heard Dean say from the library. He sounded afraid. Dean was never afraid. You prepared for bad news as you walked back inside. You went back to Dean and found him in despair, looking around the bunker. Dean wiped a hand over his mouth down to his chin, and rubbed his scruff for a while. His eyes had become watery now that the realization came down on him. You smelled the air and scented a familiar fragrance, a mixture between sulphur and tobacco. There was a note on the table, you reached for it and read it out loud.

"I'm sure your pretty boy angel expects you to save him,
I borrowed his vessel for a while, if you don't mind...
Negotiations with Heaven.. Hell..
Keeping up appearances...
What do you say, trade for a trade?
xxx"

"Damned Crowley!" Dean shouted, and kicked over a pile of books on the table. Crowley got damn serious about this. "I'll call Sam" Dean said as he reached for his phone in his pocket. Sam was currently doing an investigation on his own, he had left you and Dean in private the afternoon and went out soon after.

[…]

Sam walked out of the building where the crime scene was located, just in time. He reached to the door knob from the Impala when his phone rang in his inner pocket. Sam answered when he saw it was Dean calling.
"Dean?" he said as he got in the car.
"..What?" his voice sounded rather high pitched after hearing what had happened. "Ye—Yeah okay I'm on my way" He raced away from the crime scene and went back to the bunker. He was still in his FBI suit when he drove the Impala into the garage.
Sam walked into the library to find you and Dean sitting in silence. Neither of you expected Sam to know what to do, so neither of you looked up when he came in. Either Dean lost you, or he lost Cas. Both was horrible, considering Dean had to pick a side. Or play smart, but neither of you knew how to outsmart the King of Hell.
"Do you have any idea where he took Cas?" Sam asked. Dean handed him the note, but said nothing. Sam read the note in silence, the puppy frown starting to form on his forehead. "We'll figure this out" he said as he looked at the both of you. Sam's phone went off in his inner pocket. He took it out to look if it was urgent, but watched in distress as he saw the number "666" on his phone screen. "It's.. Crowley" Sam said.
"Put it on speaker" you said. Sam answered the phone and put it on speaker, as you said.
"Crowley!"
"Moose! So you heard what's up?" you heard Crowley say on the other side. "What do you say?" You weren't planning on giving in already, but you didn't know what to say either. "Don't be shy!" Crowley whined after a moment of silence.
"What are you planning on doing with Cas?" Dean asked in concern, somebody had to say something. Then again, Crowley might be tricking you all.
"If.. You decide to play along, I will return him," he replied, "But.. If you decide to keep your girlfriend," he spoke with laughter. "Cas is going to pay for the price"
"Meaning?" Sam bit back.
"Moose is sharp today!" Crowley chuckled. "Meaning, his vessel will be in use for Hell. Now that I have power over Castiel, I can use him to negotiate with Heaven. And when that is done, Heaven will be mine." All three of you listened to Crowley's explanation, feeling shivers down your spines.
"But, Cas is still somewhere in there?" Sam asked.
"That's right..," Crowley answered in a sigh. "I oppressed him in his vessel with a sigil, he has no chance of escaping now" Crowley grinned at his phone. This sounds pretty serious. "Now, Metatron is having a rendezvous avec Cas in about about.. Five minutes from now. If you'll excuse me, I have to witness this," Crowley said after a while. "Let's say, I give you and the Hardy boys one day from now to decide whether you let this happen or not"
Sam sighed and was about to speak up when the connection was already lost. You took a huge breath, the realization coming down on you now as well. You might die. Or else Cas might die, either way you don't want to be responsible for any of the options.
"I knew we couldn't trust the bastard" Dean growled. "Still defending Crowley's position?" Dean asked you. You shook your head, not knowing anymore why you actually defended him.
"Do we have a plan?" you sighed, as a tear rolled down your cheek.