So hey guys. This is my first fic on this account but not my first ever. Still... For some reason I decided 'let's make it a drabble.' Credits to fortheloveofotps on Tumblr for fangirling with me about 9x11, spawning the conversation that led to this fanfic. Here goes. Let me know what you think!

Disclaimer: I own no characters. I also do not own the first two lines of dialogue. Those belong to the folks at Supernatural. If you thought I owned either of those then wow thanks but no.

PS) Happy Birthday Dean Winchester. Here's to a good one. Try not to die again, idjit.

EDIT: The guinea pig's name is changed for good reasons.

"Well, they didn't have a guinea pig, but we do," Sam stated, peering over Cas' shoulder at the book.

Cas looked up in surprise, his eyes narrowing the way they always do when he's confused. "You have a guinea pig? Where?"

Sam laughed, "It's an expression, Cas. It means someone to test on or—never mind."

"So you don't have a guinea pig?"

Sam was about to confirm, but one look at Cas' face and he knew he wouldn't be able to. The guy was having a hard enough day as it was, what with the loss of PB&J.

"If I tell you a secret do you promise not to tell anyone?" he asked.

His companion nodded eagerly.

"All right, but you especially can't tell Dean, he'd throw a hissy fit. You know how he feels about pets…"

"I won't tell anyone, Sam."

"If you swear…"

"I swear. What is the secret?"

"The reason I keep my hair so long – besides it looking fabulous – is so that my little buddy Percy can live in there. He's a hamster, which is kind of like a guinea pig, I suppose."

Cas' eyes widened in wonder, "You do have a guinea pig, then?"

"Well, no but—" Sam sighed seeing that Cas was not to be bothered with the difference. "Yeah. Yeah, Cas, I have a guinea pig. He's a real sweetheart; he likes to burrow himself in my hair. Sometimes at night, I let him out and he runs around… I even put a cage under my bed for him, now."

"Can I… Can I touch him? You have to let me touch him, Sam."

"I think I could do that, sure," he laughed, leaning over so the shorter man could have easier access. "He's a bit shy but he'll probably stick his little head out soon enough."

A warm weight settled on his head, petting gently. A scratchy, ticklish set of paws resituated itself, eliciting a laugh.

"Sam! Sam he came out!"

"I can feel! What do you think, isn't he cute?"

"He's adorable. Why did you not tell me he was in there? Sam, how long have you had him?"

"A few months now, I guess. I know Hunting isn't the safest life for such a little guy, but I couldn't help myself. Dean and I were working a case a while back and I went to interrogate a pet shop owner. While I was waiting, I saw this little guy. He was adorable and I missed having a pet so later that day when different people were working, I went back to buy him."

"Why does he stay in there all day? Animals like to be free, I understand, and rodents aren't particularly lazy."

"I don't know, I suppose he's just an oddity. Do you still promise not to tell Dean? He would never forgive me… Or let it go."

"I promise… on one condition. I get to pet him whenever I want."

Sam grinned, "Deal."

Four weeks later.

Dean had been back with Sam and Castiel for a few days now, and he couldn't help but notice how off his best friend was acting. For starters, while he was obviously pleased that Dean was back, he had been shying around him… again. To add to the strangeness, Cas kept randomly petting Sam's hair. Not like that wasn't amusing. Dean wondered vaguely whether it was because he had a fascination with the princess locks, or if it was something more. They couldn't be… No. There was no way Cas and Sam would be dating. Dean was ninety-nine percent sure his brother was straight. As for Cas… While he could not be sure the angel was completely straight or even understood gender fully, he was almost positive that Cas had planted the Winchesters firmly into the friends list of his strange mind.

The question remained; what was up?

More and more over his fourth week back, Dean caught the angel stroking Sammy's hair before snatching his hand away the second Dean came into sight. More and more, jealousy overcame him in waves. More and more, Dean was tempted to hide in the shadows and watch to see what would unfold. One day, he finally did.

It was a Tuesday when Dean went to get a beer from the fridge and saw Sam huddled over some books at the table. Cas was beside him, facing his head, and petting at the hair intently. Dean watched for a minute, but nothing continued to happen.

"I don't get it," he spoke from his spot against the wall.

Sure enough, Cas yanked his hand away, sitting up straight and blushing furiously. Even Sam gave a little jump.

"What don't you get, Dean?" the younger Winchester asked.

"Why's your hair suddenly so fascinating, Sam? I mean, come on, Cas, you've known us for how many years and only now you've taken up petting the mane?"

Cas' eyes narrowed in confusion, "Why is it so important to you?"

"Well I mean, you've never pet my hair like that, and I have some pretty fantastic hair," Dean scoffed.

"Perhaps, but you do not have a guinea pig in your hair, Dean."