Sam always knew they did this. It could have been because of the way they looked at each other with lustful eyes or the subtle touches that were not so platonic, but it was mostly the way they made each other smile. Sam wasn't even sure that Cas even knew how to smile and it's damned hard to make Dean, a man who's been to hell and purgatory and back, form his perfect lips into a genuine smile. Yes, Sam always knew what Dean and Cas were up to. And maybe he was a little bit jealous.

Of course, Dean would never admit it, but it was impossible to miss. However nothing was really confirmed until the day Sam walked in on it.

It should have been awkward. And it would have been, if it hadn't been so hot. Cas and Dean were moving so passionately together, making love to one another like they were the only two people in the world. They didn't even stop. Dean, that cocky bastard, only moved faster and grunted louder as he grinded against his lover and pushed into his ass. Sam couldn't even move. The only movement his shaking hands were capable of was a tentative but not subtle slide down his body and onto the zipper of his jeans, pulling it down to expose his hard cock. He proceeded to work his cock in time with Dean's thrusts. Dean knew that his baby brother was jerking off watching him fuck their best friend, but that wouldn't slow him down. He only changed his pace to turn around and wink at Sam. Sam came harder and quicker than he'd ever come before. He ran into the bathroom to clean himself up before leaving the motel room as quickly as possible with his eyes squeezed shut as if he didn't want to watch any longer. He did.

When Sam came back, Cas was gone and Dean was, fortunately, fully dressed.

"Hey there, Sammy," Dean said as if nothing had happened.

"Um- Dean… should we talk about this?" Sam asked, uncommonly shy.

"What's there to talk about? You walked in on me fucking our friend and jerked off," he answered with his usual confidence. "And it was awesome."

"Dean, be serious."

"I'm very serious. Now the only question is, why didn't you join us?"

"W-what?"

"Don't pretend you didn't think about it. That big, sexy cock pounding Cas's tight ass. Making those pretty little noises you made just watching. I can just imagine how much louder they'll be when you get the real thing."

"Yeah… um, yeah. Cas…" Sam said, slightly disappointed that Dean thought he wanted Cas. He thought it was obvious. He wanted Dean. There was silence before Dean came to a realization.

"Oh. Ooooh, Sammy you filthy boy," Dean said, so close to Sam's face that, if he stuck his tongue out, he could lick his brother's lips.

"Wh-what?" Sam stuttered again.

"It's not Cas, is it?" Dean asked moving in to whisper against Sam's ear, tilting his head up slightly to reach. Sam looked down, his face red and overheating. "It's your own big brother. Oh, Sammy, my naughty little bro."

"Stop it, Dean."

"Is it me, Sam?" he asked.

"Yes it's you, Dean, it's always been you."

"Okay."

"Okay what?"

"Okay get your clothes off what are you waiting for?"

"But what about Cas?" Sam asked but wished that he hadn't. He didn't really care all that much. He couldn't.

"What about Cas?" Dean asked.

"Well, aren't you like… in a relationship?"

"Oh, Sammy, you know I don't do relationships." Sam looked disappointed upon hearing those words. Dean took notice. "But you're different Sam. I'll always be here with you. This isn't a one time thing if you don't want it to be."

"You'll break Cas's heart. Don't do that to him."

"He knows, Sammy."

"Knows what?"

"It's you, Sam, it's always been you."

Finally they were kissing. Years and years overdue, but they finally did it. Their mouths moved against each other like gears, so in-sync. It moved too slow and too fast at the same time and soon they were both naked. Dean touched Sam all over and Sam returned every gesture, equally enthusiastic and maybe a little bit more desperate. Dean kissed down Sam's body as his hands moved from the small of his back to his hips and against his ass. Dean licked the underside of Sam's cock from base to tip, making the sexiest noise Sam had ever heard. And Cas heard it too.

He didn't mean to make himself visible. Or rather, that's what he convinced himself. It was the same damn thing Sam did, but Sam was very visible (he wasn't complaining). It was almost identical, except this time Dean stopped.

"C'mere Cas," Dean said, after looking at Sam for approval. Sam nodded quickly, much more focused on Dean's mouth returning to his hard dick. Cas squinted his eyes and tilted his head. Dean thought it was fucking adorable, and he didn't throw that word around often. "Get over here you sexy thing."

Cas was quick to remove his multiple layers of clothing to approach the queen sized motel room bed. There wasn't much room, but the three of them were fine with staying close together.

"Sam, you ever take a cock before?" Dean asked, before Sam bucked up and made him take his now-throbbing member into his mouth again. Sam laughed at that.

"Once or twice… a month…" Sam answered. Dean moved his mouth from the other man's cock and looked him in the eyes.

"Are you gay, Sammy?" Dean asked. "Is my baby bro a raging homosexual?"

"Said the man bent over with a dick in his mouth and another man eating his ass." Dean didn't reply to that remark, he just moaned around Sam's cock as Cas fucked him with his tongue and jerked his own prick.

Dean got up and moved swiftly as possible to grab the lube. His brother may have done this before, but that only made Dean all the more determined to be the best he'd ever had. When he returned from digging around in his duffle, Cas and Sam seemed as though they'd forgotten he existed. The way they kissed was so obscene it made Dean want to come right then and there, but he wanted to make love to his Sammy so much more. Dean spread Sam's legs and slid a slick finger he into his tight asshole, feeling tentatively before moving his finger in and out.

"More, Dean," Sam moaned.

"Yes ma'am."

"Jerk."

"Bitch."

"Would you two just fuck already?" Cas interrupted in a blunt-as-ever tone of voice.

After Dean worked Sam's ass with two, then three, then four fingers, he aligned himself against his brother's tight little hole and when Sam gave him a little, shaking nod he pushed in.

"Move!" Sam yelled, impatient. He had, after all, been waiting damn near 15 years for this moment.

"First I found out he's gay and now he's a cockslut? Ain't today just chock full of surprises," Dean said aloud to no one in particular.

"You say that like it's a bad thing," Cas said, "but from where I'm sitting, it's the best thing there is."

With that, Dean obeyed his younger brother and moved slowly in and out. It was so much more than sex; it was making love. It was body worship. All the while, Cas was kissing Sam in that same way that made Dean squirm with lust and jerking his thick cock to the rhythm of Dean's thrusts.

"I'm gonna-" was all Sam could get out before he moaned louder than ever before and Cas stroked him through his orgasm. Shortly after, Dean came into Sam's ass and pulled out. He realized that the two of them hadn't been paying much attention to Cas, so despite his fatigue, he leaned over to suck Cas's hard cock the same way he did to Sam until his angel came into his mouth. What Dean didn't swallow, he kept on his tongue so Sam would taste Cas while they kissed. It was a sloppy kiss but it was nonetheless the hottest thing either Winchester had experienced.

When they were all sexed out and cleaned up, Sam got up from the bed and headed to sleep in his own, however Dean caught his hand before he could leave.

"If you leave me right now, I swear I will spank you," Dean warned.

"Is that a threat or a promise?" Sam reciprocated.

"That's a promise. Now let me hold you."

"Okay, Dean. But next time?"

"Yeah?" he said, glad to hear that there would be a next time.

"King sized bed."

"You bet."

And the three boys definitely didn't cuddle all night.