Dean might never be able to go into the shower room again. The sight that had greeted him was burned into his brain, and he would likely see it any time he stepped into the room. Forever.

At least the hunter knew now why his brother had been so disinterested in going out with him lately. He didn't need to go out if he had someone at home waiting for him. And wasn't that just a fucking weird thought.

So, Sam and the angel. What the fuck? How had he missed something like that? It was fairly clear from the scene that he walked in on that it wasn't the first time this had happened, either.

When Sam stumbled into the library some half an hour later, Dean was sitting there waiting for him. He watched his brother's eyes widen in surprise, and then his face closed off trying to give off an air of not caring that Dean was home.

"Well, you're home early." He said, dropping into the seat next to Dean and popping open his laptop.

"Yeah, slim pickin's at the bar tonight. I decided it was just as well that I come home and drink as much as I want." He raised his glass full of amber liquid. He didn't bother to mention that it was his third one since he'd gotten home. He'd need all the booze in the world to help him forget the very disturbing view he'd gotten of his brother.

"I wasn't expecting you back until morning." Sam said nonchalantly while waiting for his computer to finish booting up. Well, that was an opening if Dean had ever heard one.

"Yes. I noticed." He let loose a full body shudder.

"What?" Sam's eyes snapped up to meet his, and Dean could see the fear in his eyes.

"I uh… tried to take a shower when I got home." Dean raised an eyebrow at his brother and leaned forward on his elbow. The hand now by his face held the glass of sweet memory-erasing liquid. "It was already occupied."

All of the color drained from Sam's face, and his features went limp.

"Over occupied I'd say." Dean added, just in case his brother didn't catch the implication. Although Dean knew he had. Sometimes he just liked to push things.

Sam was still just staring at him, slack-jawed.

"You've got nothing to say to that, then?" Dean pressed the glass to his lips and took another large swallow. "Maybe I should be asking Cas about this instead."

They both knew that was a threat. The angel had no tact, and would not be embarrassed at all to answer any of Dean's questions. Possibly in way too much detail. Sam's mouth snapped shut, and he swallowed audibly.

"Uh, what… what do you want to talk about, exactly?" He ran a nervous hand through his hair and bit his lip. Dean rolled his eyes. It wasn't like he was going to ask for intimate details. Or any kind of details. He already knew way more than he would ever want to.

"How long has this been going on?"

"What do you mean?" Sam shifted uncomfortably in his seat, and looked away. He was such a terrible liar he couldn't even keep it together when he was just trying to avoid the subject.

"Well clearly it's not the first time this has happened." Dean raised his brows at his brother. Avoidance was a game that all Winchesters played, but they were also stubborn as hell. He wouldn't be deterred.

"What makes you say that?"

The avoidance was going to get him in trouble now, and Dean rolled his eyes as he answered. "Because you're not the type of guy that takes someone new to the shower to fuck them up against a wall." He looked pointedly at his brother. They both knew Sam was a hopeless romantic and would never do something like that.

"And Cas doesn't really seem like the kind of guy that spends his first time begging for you to do it harder."

Sam blushed as Dean said it and he knew that his brother was just beginning to realize the extent of what Dean had actually seen.

"Yeah, take that embarrassment you're feeling now and multiply it by like a hundred, if you want to know how it felt walking in on your baby brother banging your angel like the world was ending."

Sam's blush spread even farther at the comment, and Dean couldn't even find it in himself to feel bad about it. Not that he was trying. He was traumatized for life, and his brother deserved every bit of the discomfort that came with this discussion.

"So, how long have you been hitting that?" Dean grinned at the disgusted look on his brother's face at the phrase.

"Come on, man. Don't say it like that."

"Well, it's not as if I can say 'making love'. The dirty shower sex I walked in on certainly wasn't that."

"Okay, can we get beyond the shower sex part of this conversation now?"

"You still haven't answered my question." Sam's look of confusion said he didn't remember what question he was meant to be answering.

"How long have you been glazing that particular donut?"

The look on his brother's face was encouragement enough to keep using euphemisms.

"God, ew. Stop that." Sam shook his head with an offended look, but still hadn't answered the question. Dean wondered if the younger Winchester was using Dean's game as another avoidance tactic. Too bad for Sam, he had a million of them. His brother would break.

"Come on man! How long have you been putting the ranch in that Hidden Valley?"

"Dean! Knock it off!"

Dean grinned.

"I just want to know how long you have been tickling the angel from the inside!" He exclaimed, as if it were a perfectly reasonable request.

Sam groaned and dropped his head into his hands. That was a sound of defeat, and Dean delivered the grand finale.

"How long have you been testing his suspension? How many times have you checked his oil with your dipstick? I just want to know when you started filling his gas tank, man."

Sam's head popped up and he glared at his brother, a blush still staining his cheeks.

"Okay! Enough! God! I hope he can't hear you, you fucking pervert."

"So, you'll tell me how long you've been Cas' personal chimney sweep?"

"Yes! Just stop!" He even looked resigned, and Dean mentally patted himself on the back for a job well done.

Sam took a deep breath, and there was a long enough pause that Dean almost started in on him again.

"It's been a while." Sam had the decency to look a little ashamed, not meeting his eyes and idly running a hand along the table's edge. Dean's eyes narrowed.

"How long is a while?"

Sam shifted in his seat, but raised his gaze to look him in he face.

"Six months." He shrugged a little. "Maybe longer."

What the actual fuck? Six months? They had been together for half a year and Dean hadn't seen it. And they hadn't bothered to tell him, either.

"So... is this some kind of stress relief thing? Or is there something more going on here?" His protective instincts were kicking in full force, and he couldn't even tell if they were there for Sam or Castiel.

Sam looked down again, and his voice was a bit quieter when he answered. Seemingly so the angel wouldn't be able to overhear whatever he said.

"I don't really know. I mean, it's more than that for me." And he was blushing a bit again. This fucking kid was once the vessel of Lucifer. Jesus Christ.

"You guys haven't talked about it." Dean said it as a comment, because he already knew the answer if it had been a question. Another classic Winchester move. Don't bother with the communication.

"Uh, not really. No."

"So you just get down to it whenever I'm not around?"

"No! I mean, we talk. We just haven't talked… talked about feelings or whatever." Of course they talked. They probably talked all the time. Sam was known to be a girl about these things, and he certainly wouldn't have just been fucking him and leaving him. Not that Dean wanted that to happen to Castiel anyway. Fuck, this was confusing when he cared about both of the people involved.

"Well, I guess I should ask the obvious here. Why haven't you talked about your feelings? You love talking about your feelings!"

"I guess… I'm afraid of what he might say. And I don't really want to fuck up what we have going on right now. It's pretty great." His embarrassment and fear melted into a slightly dreamy smile at that. It made Dean want to gag.

"I don't want to know about the quality of your love making ." He said the last bit sarcastically, making sure to emphasize it.

"Sorry." Sam grinned sheepishly. "It is amazing though." His grin turned devilish, and Dean knew his brother was going to try to make him as uncomfortable as he had made the other man earlier. "Probably the best I've ever had."

"Ew, please stop. I don't want to know." Sam's grin only grew.

"He's just so eager. And responsive." Dean cringed. He did not want to picture the angel that way.

"I'm glad that you enjoy our relations, Sam." The slightly amused voice came from the doorway, and both of the Winchester's attention were drawn to it.

"Cas!" Even Sam's voice was embarrassed, and Dean grinned as he turned back to his baby brother. He was definitely going to win this round, now that the angel had shown his face.

Castiel took a seat with them, watching Sam squirm.

"Sorry, Cas. I was… Well, Dean was… I'm sorry." He seemed to decide it was pointless to try to defend himself and just apologized instead.

Dean had to admit he was a little interested in watching the scene. Now that he knew what was going on between them. He was also curious to see if he could figure out how the angel felt about his brother. He knew that Sam was likely falling hard for Castiel, and he hoped that the angel was on the same page.

"It's alright, Sam. I quite enjoy having intercourse with you as well." The statement caused both of the brothers to groan, and Sam's embarrassment to come back full force.

"Oh my God! Don't say things like that while I am in the room! " Dean could feel his own face heating.

"Your penis seems to be the perfect size for prostate stimulation." The angel continued, completely ignoring the eldest brother's protest. "I also quite enjoy the skill you employ with your mouth."

Dean was so uncomfortable at this point he thought he'd end up squirming right off the edge of his chair.

"Please. Stop. Talking." He begged, to no avail.

"You are also quite visually pleasing. Especially when you are aroused." Castiel smirked at Sam as he said it, and Dean turned disbelieving eyes on his brother.

Dean saw a look of understanding cross his brother's face, and watched the embarrassment quickly fade. How could he be less embarrassed with Castiel spouting all their bedroom secrets? It took him an inordinate amount of time to figure out what was happening.

"Cas, are you trying to make me uncomfortable?" He was a little shocked, to say the least.

"Yes. You were trying to make Sam feel uncomfortable earlier." Castiel was completely unashamed at being caught out.

"Well, son of a bitch." Dean guessed that answered his question at least partially. You didn't get protective about people you didn't care about.

"Perhaps you would like me to go into further detail about what it feels like when Sam… what's the phrase? Butters my biscuit?"

As uncomfortable and embarrassed as the brothers were at that point, nothing could have stopped them from nearly laughing themselves to death when the angel said that. There were actual tears in his eyes when Dean looked back up at Castiel to see him smiling fondly at the two idiots he had gotten stuck with.