First things first.
I DON'T OWN SUPERNATURAL! ALL RIGHTS BELONGS TO THE RESPECTIVE OWNERS OF THE SHOW!

Requested by an anonymus user on tumblr :).
Warning: It's a tickle-fic
And again i am so very sorry for grammer/spelling mistakes.
Don't forget: My first language isn't english and again sorry if some sentences are squeezed together -_-.

Hope you like it :D

Sensitive Knees

Sam had absolutely no idea how he got himself into this kind of situation.

A few minutes ago Castiel had appeared out of nowhere and he was almost scared to death when the angel had put a hand onto his shoulder, startling him so much he almost fell off of his chair.

After a death glare and a growl he had asked the angel what he wanted and when Cas started to tell him he got some new information about the case the Winchester brothers were working on at the moment, he had put a hand on Sam's knee.

At first Sam felt very uncomfortable, but realized that Cas just used his knee for support.

It still was awkward, but he decided to keep his mouth shut.

Castiel couldn't know that humans would feel uncomfortable when someone would touch them in certain areas, just like his knees.

The moment the angel accidentally squeezed the area above his left knee, he couldn't ignore it anymore. Cas' words were forgotten the moment he squeezed his knee again and this time Sam couldn't keep his body still and with a little shriek he jumped so hard that his knee hit the underside of the table.

He would never forget the shocked expression on Castiel's face.

Of course the angel didn't know about the ticklishness of his knees.

How should he?

Sam wasn't even sure if the angel knew what tickling was in general.

And now he sat there with a flushed head, totally embarrassed.

In front of him an angel of the lord who looked as confused as a little child that didn't understand the whole damn situation.

"Sam? What was that? Are you okay? Did I hurt you?"

There was so much concern in Castiel's words that Sam had no other choice than to tell him what was going on. But before he could even say one single word, the angel's hands were back on his knee, poking and prodding, even squeezing a little which made him jump and shriek again.

"Sam! What is wrong? Does this hurt?"

And again he squeezed…and again and again until Sam couldn't take it anymore.

Before he erupted into loud laughter, he quickly grabbed Castiel's hands and pushed them away.

"Stop it Cas!"

"But why? It looks like it would hurt if I do this."

"H-hey…ACK!...Stop it!"

Castiel looked up, looked right into Sam's face…and knitted his brows together when he saw how red the hunter was and…was that a tiny smile on his lips?

"Sam? What is wrong? Please tell me. Are you injured? Does this hurt you?"

"N-no. No Cahahas! S-STOP!"

The angel raised an eyebrow when Sam started to giggle and he shoved at his hands which were back at his knee, squeezing the top of it until the hunter tried to get away from him.

"P-please. That…thahat tickles Cahahas. Stohohop!"

"Tickles?"

The angel looked at his hands, confusion was written on his face.

Why was Sam laughing when he touched his knee?

He didn't understand that, but he had to admit that it felt good to make Sam laugh.

He hadn't laughed in a very long time and if a simple touch to the human's body could make said human laugh…

Castiel's lips turned up into a gentle smile and his hand started to squeeze the knee rapidly now.

But he couldn't keep this up for too long because Sam squirmed around so much that he soon fell to the ground, giggling like a child and he quickly crawled away from the now mischievous angel whose lips quirked up into a small grin.

That was fun…

"No Cas! Don't you dare! Go awahahahay!"

Sam tried to get away from Castiel, but it took only one swift movement of the angel's hand and Sam lay on one of the motel beds, unable to move and already giggling with anticipation when Cas sat down next to him.

"What is wrong with you Sam? What's so funny?"

Sam could hear the amusement in Castiel's voice and it made the whole situation so much worse.

"I-I tohohold you what is wrohohong! Now…go awahahay!"

"Hmm no, I don't think I will go away. I stay here with you, because I want to know why you are laughing when I do…this!"

"ACK! NO! Cahahahas! S-STOP!"

The evil grin on Castiel's face grew when the volume of Sam's laughter rose in pitch and he kept squeezing Sam's knees with his hands until the young hunter was shrieking with laughter, pulling on his invisible bonds, trying to get away but heck, he couldn't even move!

"Stop? But why? You are laughing and as far as I know a human feels good when he is laughing. Why should I stop than?"

"Damn it Cahahas! J-Just STOHOHOP!"

Just in that moment the door to the motel room swung open and Dean entered the room, hands full of bags with food.

"Hi Sammy, sorry it took me so long. There was this waitress and I just…"

The moment Dean heard the loud laughter behind him and turned around to face Sam he couldn't believe his eyes.

His little brother lay on the bed in front of him and Cas leaned over him, hands squeezing at his knees which made the younger hunter laugh almost hysterically.

"Cas? Sam? What the hell is going on here?"

The angel turned around and Dean couldn't believe his eyes yet again when he saw the big and evil grin on his best friend's face.

The moment realization hit him, the older hunter crossed his arms above his chest, lips quirking up into a big, knowingly grin.

"Looks like you have found out about my little brother's weakness, huh Cas?"

"D-DEAN! DEAN HEHEHELP MEHEHE PLEAHAHASE!"

Dean just ignored the pleading looks he got from Sam.

Instead of helping him, he threw his bags onto his bed and sat down next to Cas.

"Sam told me it would "tickle" when I do this…"

"AHHH! NOHOHO CAHAHAS!"

"…and I found it funny. But he doesn't look like he would enjoy this Dean."

Dean's grin widened.

"He is such a little liar. He is enjoying this very much Cas. Am I right Sammy?"

Sam's cheeks flushed even more and he tried to hide his face in his arms, laughing more when Dean let his fingers walk up and down his sides and ribs.

"No Dean…P-PleahahahaAHAHSE! AHHH! NO! D-DON'T HELP HIHIM! H-HELP MEHEHEH!"

Dean laughed along with his brother and he dug his fingers deeper into his armpits, finding the perfect rhythm to drive him up the wall. When Cas found a little sweet stop behind his knee all hope was lost and Sam erupted into loud, booming laughter until tears started to build up in the corners of his eyes.

"There is no way we will stop this Sammy. You have been a grumpy, little bitch for far too long and it is time we change your bitchy attitude! Come on Cas, get him good!"

Castiel's grin widened, if this was still possible, and he shot a wave of his grace into Sam's body, which made the hunter buck as good as he could and his laughter turned silent for a few seconds.

"Ouch! Hey! Sammy! What do you think you're doing? Are you crazy?!"

The only response Dean got was more laughter.

"What did he do?" he heard Cas ask and he grumbled.

"He bit me!"

Even the angel had to laugh at this and when Dean saw the smug grin sparkling in Sam's eyes he growled like a hungry wolf and slipped his hands under Sam's Shirt and scribbled over his soft belly.

When he found his belly button Sam screeched.

"Biting your big brother. Really Sammy? And then you dare to laugh at me?! Cas and I will give you something to laugh about! Cas, you should try his feet!"

The moment Castiel pulled his shoes and socks off of his feet Sam knew he was screwed.

This would be a looooooong day…

The End