If you asked anyone who knew the Winchesters which of the brothers was the more studious one, they would all say Sam. After all, he was the one that got a college education and that did most of the research when it came to hunts.
But those people didn't know what Dean was like when Cas was away.
After about a year of them awkwardly dancing around each other, and Sam almost choking on the sexual tension, they'd finally gotten together, and had spent a hell of a lot of time together ever since.
So whenever Cas left, Dean wasn't too happy. He missed having Cas next to him at night, and even missed that damn trenchcoat.
So to distract himself, he threw himself into his Men of Letters work, with help from Sam and Zeke.
Dean had broken the news about Zeke to Sam several weeks ago, explaining the situation as well as he could. Sam had been surprisingly understanding about everything, and had allowed Zeke to stay inside of him for as long as it took. Ezekiel also happened to be a helpful source as well, supplying them with information about nearby monsters, or just anything supernatural in general.
They were currently working on a case involving a very strong demon or angel-like thing in New York. It didn't fit the description of anything they'd come across before, and it was bothering all of them, Zeke especially.
This thing, whatever it was, was extremely powerful, and didn't seem to move from place to place. It would occasionally disappear suddenly, only to appear with a human, use the human for something, then return the human to wherever it came from.
Dean suspected a vampire, Sam an angel, and Zeke thought perhaps a cross between the two, something previously thought entirely impossible.
Two of them needed to go to New York and figure out what was going on. Ezekiel refused to go, insisting that it was too dangerous for him, and they were too worried about Dean getting killed by not being careful enough to let him go alone. Their only option was to wait for Cas to return from wherever it he was and make him travel to New York with Dean.
The thing is, the reason why Cas had to leave was to keep other angels away, and if either Sam or Dean knew where he was, it would put them all in danger. So this meant a lot of waiting on Dean's behalf.
They left the day after Cas finally returned, because Dean insisted that he and Cas had at least one night together on a comfortable bed before having to resort to old motel rooms and the backseat of the Impala.
Sam had agreed, but made them get up early the following morning so that they could make the most of daylight hours. He'd promised Dean he'd make him a pie when he got back in order to encourage him into the car.
Although Dean was reluctant about leaving, he seemed to be fine once he actually got in the car, turning his music up loudly and singing along. Cas found this weirdly cute, and found himself also singing along to some of the songs he'd heard coming from Dean's bedroom and had come to know quite well. They stopped several times for food, and only ended up staying one night in a dodgy motel before they arrived at their destination: a fairly expensive looking apartment block in Manhattan.
Dean had detected something inside, but it didn't seem to be a demon, and his readings showed that he left during the day, almost ruling out the vampire possibility.
Cas, Dean and Zeke had all shared one theory, though, that they didn't share with Sam. Some voices on angel radio had spoken about this creature, whatever it was, saying that it was a trickster. And that meant only one thing to Dean – Gabriel.
He was a trickster, and one of the most powerful archangels, so who's to say that his death wasn't just another one of his tricks? The thing was, though, that Sam and Gabriel had history. And Sam had been devastated when Gabriel had died, and no one had wanted to get his hopes up again, hence the real reason why Zeke refused to go with Dean.
They stayed stationary outside the apartment block for the rest of the day, waiting for this trickster to emerge. He had come and gone several times that day already, but he seemed to teleport out instead of walking out the front door.
Finally, the weird creature returned, this time with a human. Fearing that someone's life was in danger, Cas and Dean hurried out of the car, grabbing an angel knife each as well as a two pistols, one loaded with silver bullets, the other with rock salt.
Using fake I.D's, they managed to get inside and past the guards. Using information from Zeke, they got the guy's room and floor number, and made their way up in the lift. The hallway was silent, and there was no sign of blood nor a sound of someone being brutally murdered/bitten.
Cas looked at Dean and gave him a nod of confirmation when he gestured to the door. The lock was easy to pick, and the two men entered, their guns out in front of them. Dean lead the way in, trying to stay as silent as possible. They'd checked all the rooms, except the bedroom, and were tip-toeing over to it when Dean felt the cold metal of a dagger against his neck.
"What brings you to my home… hunter?" A cool voice greeted. "And an angel that lost his grace too, how… interesting."
Dean struggled, but the thing behind him was too strong. "What are you?" He managed to get out, before the dagger was pressed back against his neck even more firmly.
The creature chuckled. "I see the apocalypse really did distract you from other current events."
"How do you know about the apocalypse?" Cas asked. He was pinned against the wall by a strong hand, and couldn't move either. "Are you a demon?"
The figure turned to him, and Cas was now ninety percent sure this person was a vampire. They had the stereotypical pale skin, matched with dark hair. Not to mention how silently he was able to sneak up on him and Dean. "Me? A demon? Your theories astound me, graceless angel. And shouldn't I be the one asking the questions? I'll ask again, shall I? What are you doing in my home?" He spat the last few words out.
Dean was almost going to say something snarky about barely being able to speak because a dagger was pressed to his throat, when the bedroom door in front of them opened and revealed a very familiar looking shirtless man.
"Loki, when you feel like explaining why you suddenly left the bedroom, I'd be happy to listen." The other man said.
"Loki?" Dean asked. "As in Gabriel Loki?"
Loki reluctantly vanished the dagger and let go of Cas. "As in the god Loki. That wretched angel took my name and we are by no means connected." He said through gritted teeth.
Dean glanced over at Cas to make sure he was alright. Aside from looking annoyed about being snuck up on, he seemed fine. "So what the hell is a god doing on Earth?" Dean asked.
Loki glanced over at the other guy, Dean still couldn't figure out his name. Once the guy stopped staring at Loki and allowed Dean a proper look at his face, he could figure it out. "Trust me, hunter, when I say I am not here by choice." Loki muttered.
The other man snorted. "Oh please, it's your own fault and you know it. If you decided to, I don't know, not send an alien army to destroy Earth, you would still be frolicking around on Asgard with Thor."
"Thor, the God of Thunder?" Dean interrupted. The guy in the doorway turned to face him, and that's when Dean recognized him. "Shit, you're Tony Stark!"
Tony gave a dramatic bow. "Congratulations, you know your celebrities. And you are?"
"I'm Dean, and this is Cas." Dean purposely avoided giving his last name.
"So, Dean and Cas, what are you doing in my partner's apartment?" Tony raised an eyebrow.
"Partner? You're dating this guy? What happened to Pepper?" Dean asked incredulously.
"She's fine, we just didn't click." Tony shrugged the question off. "And yeah, I'm dating this guy." He winked at Loki who just rolled his eyes and folded his arms over what Dean now noticed to be a very nice and bare chest.
"Wait a minute…" Dean paused, putting the pieces together. Both men were shirtless, and Tony had just come out of the bedroom… "Fuck, did we just walk in on you two having sex?"
Eyes widening, Cas turned to Dean. "You are talking to a very dangerous and powerful god, Dean, you should remember that."
"Yeah, but Cas, it doesn't matter, this is Iron Man we're talking about." Dean argued.
"Is that supposed to mean something to me?" Cas retorted. "Because it doesn't."
"He's like this superhero that sleeps with heaps of women, he's a billionaire, he's really fucking smart, and he has this suit made out of iron-"
"It's gold titanium alloy, actually." Tony interrupted. "And did you just come here to fanboy with a gun or is there actually a purpose to your visit? Because Reindeer Games and I were kinda in the middle of something-"
"Don't call me that." Loki muttered sharply, at the same time Dean said; "Reindeer Games?" and laughed.
Cas and Tony sighed simultaneously. "We're here because a friend of ours heard about some strange and powerful creature on the loose in New York. He was worried because he kept on disappearing then re-appearing with a human, and he thought the human might be in danger." Cas explained, bored already. He just wanted to go back to the bunker and read a book on his and Dean's bed, without being interrupted by Sam and/or Ezekiel.
"Well, as you can clearly see, I'm not in danger. Unless, of course, you don't believe me and we have to invite you into the bedroom for you to see for yourself." He grinned at Cas and wiggled his eyebrows suggestively.
Luckily, Loki chose that moment to focus on his lover/partner/boyfriend. "You need to stop inviting others into our bed, Anthony, it gets tiring for me having to drag them out every time they say yes."
"Your bed." Tony corrected, and both Dean and Cas noticed the frown that appeared on Loki's face.
"Someone's not into the idea of polygamy." Dean whispered to Cas, who then chuckled.
Loki shot them a dark look. "Oh please, I've had more interesting sex in the past two years than you two will in your entire lives."
"I doubt it. I've slept with an angel. Twice." Dean snorted.
Loki rose an eyebrow and smirked. "Really? Well, I fucked a horse to save my realm."
Tony was clearly familiar with that information, but Dean and Cas stared at him with wide eyes, looking completely shocked.
"He also gave birth to an eight-legged horse." Tony pitched in helpfully.
"I'm a shape-shifter." Loki explained. "So I can do this." He turned into Dean. "Or this." He turned into Cas. "Or maybe even this…" He trailed off, going deep into Dean's mind and finding his most hidden kink. He smirked to himself and shape-shifted into Cas again, this time wearing nothing but panties and a tie. He also included a couple of tattoos onto this new body as well, an Enochian symbol and a pair of wings on his back. He glanced at Dean and fluttered his eyelashes. "You know you want me, hunter."
Dean opened his mouth to speak but was too embarrassed to say anything. Cas was watching with a curious look on his face, and Tony was too busy imagining what Loki would like in those clothes instead of Cas.
"Change back. Now." Dean finally managed to order. He spun around to glare at Tony. "Can't you stop him or something? He's a real asshole, you know."
"Hm?" Tony snapped out of his daydream. "Yeah, no can do, Deanie boy. Loki's out of control, hence the reason he's tried to destroy two realms already."
Loki finally changed back, this time changing into one of Tony's shirts and black sweatpants. "I didn't try to destroy Midgard, I merely intended to rule it."
"Cas, this guy is creeping me out. Let's get out of here." Dean said, shooting Loki another glare and taking Cas' hand.
"Wait, you guys will be needing somewhere to stay, right?" Tony asked. "There's a floor in my tower that's just hotel rooms for staff that end up working long hours. You can bunk there if you want. Juts tell JARVIS, he's my AI, your names and he'll let you in."
"What about Edward Cullen over there?" Dean pointed at him. "How do we know he won't come attack us during the night or something?"
Loki chose that moment to grow fangs and hiss. Tony just smirked. "Don't worry. I'll easily be able to keep him occupied."
Loki's eyes lit up at this and he walked back into the bedroom, swaying his hips as he left and putting something it Cas' pocket as he walked past.
Tony pulled his eyes away and smiled. "Oh, and if you hear something in the ceiling at night, it's probably just Natasha or Clint in the air vents. They'll probably just leave you alone, but if they talk to you, you know nothing about Loki and I, okay?" Tony warned them.
"You're telling me I'm going to be in the same building as Black Widow? Trust me, the last thing I'm going to be thinking about it is you and your creepy ass boyfriend."
"Hey, as weird as he might be, I still love him, so keep your comments to yourself. You probably feel the same way about Cas." Tony sighed.
"Yeah, yeah, how sweet. But thanks for the room, though, we appreciate it." Dean thanked him as he headed towards the door.
"No problem!" Tony called out as the front door was shut.
The drive to the tower was quiet. Dean was too embarrassed by what Loki had done to say anything, and Cas was deliberating whether or not his plan would work. When they arrived at the infamous tower and got in, Cas headed straight to the bathroom, and he didn't emerge for several minutes.
When he did, though, it was worth it.
Because all Cas was wearing was a pair of panties that Loki had slipped into his pocket, and his tie.