The prank war was coming to a close, much to the relief of Sam Winchester. It happened after Sam had rigged all of the beer bottles to explode once opened and shoot the drink everywhere. Dean had wondered why Sam wasn't drinking anything for a while. So, the boys caved and made a truce that night. Sam was finally able to sleep peacefully and without fearing for his safety. So when he woke up completely restrained by bonds tying him to the bed posts, he was ready to kill his brother.
"Dean! What the hell is this?!"
But there was no answer, so then Sam started to think that this wasn't Dean's doing, and that maybe something evil was at work. He struggled in his bonds, doing absolutely nothing but putting strain on his wrists and ankles an causing his shirt to ride up, revealing a strip of skin. In the midst of all the struggling, the door to the motel room opened and in strode Dean. He was holding back a grin at the sight.
"Heya, Sammy. Glad to see you awake."
"Dean, I don't know what this is, but I don't really care. Let me go... Wait, if this is another prank, I swear-!"
"How could you not tell this was another prank? I think I made it pretty obvious."
"But we made a truce!"
"Fingers crossed," Dean did so with his fingers and smiled even wider.
"Alright, you had your laugh, ha-ha, now get me out of here."
"I will. Once you acknowledge that I'm the best prankster ever."
"For what, this? This is lame."
"You take that back!" Dean said in mock offense, clutching a hand to his chest and advancing towards the bed. Sam couldn't keep his lips from twitching at the reaction.
"More like the worst prankster ever!"
"You. Take. That. Back."
Dean climbed on the bed and straddled his brother, leaning over him, a mischievous glint in his green eyes.
"Dean, get me out. This isn't funny anymore."
"Well, you still didn't say what I wanted to hear; and you know, Sammy, I'm not above torturing you..." Dean smirked evilly, causing Sam to grow worried, "... you know, in a playful way."
That was when Sam's brows furrowed and he narrowed his eyes in confusion at his brother. Dean glanced down at that exposed skin just above Sam's waistline and he dragged a single finger agonizingly slowly across it. Sam inhaled sharply and bit down on his lip as the lower portion of his body squirmed.
"Oh, Sammy..." Dean said mockingly, not ceasing his torturous journey across that strip of skin.
"Not as long as you're ticklish, it's not. Now, who's the best prankster in the world?" and Dean jabbed his fingers into Sam's sides when he said that for impact. Sam squeaked and jumped in his bonds. Immediately though Dean went back to teasingly running his sole finger over that stomach. Sam's waist was jerking right and left, the opposite way wherever Dean was taking his finger.
"Hmm... that's an invalid request there, bro. Instead, would you like for me to jack up the torture?"
Dean ignored Sam's plea and lifted up Sam's shirt even more, revealing a good portion of his torso. The older Winchester used all five of his fingers to wiggle them all over that skin, causing Sam to laugh longer than before.
"Well, this seemed to work better. How about if I do this?" Dean used his free hand to squeeze and tickle his brother's ribs. Sam jerked even harder and laughed even louder.
The thing about Sam, as Dean knew very well, was that he didn't necessarily have a "sweet spot" like most ticklish people. He was pretty much equally sensitive everywhere, but Dean knew just how to combine his movements to make his baby brother laugh loudest and cutest. He knew how to tickle him to make him squeal, to make him belt out loud laughs, to giggle, and to make his dimples show the most. Right now he was focusing on getting Sam to belly laugh.
"DEHEHEAN STAHAHAP PLEEEEHEHEHEASE HAHAHAHA!"
"You still haven't admitted it."
Dean then dug his fingers in between Sam's highest ribs, just under his armpits. Sam was laughing hard and loud now. Dean was so elated to hear his Sammy laughing, so to further the cuteness, he leaned down and buried his face into his brother's neck. Just the stubble rubbing against his cheek made the younger Winchester giggle. But when Dean started blowing raspberries on the neck flesh and he leaned back to enjoy his work. Sam was nearly breathless with laughter and his dimples spread vertically on each cheek, clearly illustrating his happiness.
"HAHAHA Y-YOHOU'RE THE BEHEHEST EHEHEHAHAHA BROHOHOTHER IN THE WOHORLD! N-NOW ST-STOHOHOP!"
Dean did stop and just stared down at Sam. The latter was greedily taking in large gulps of air to make up for the lack of it while he was laughing. But his laughter died down to giggling when he saw his brother's face. It looked kind of startled and shocked.
"Dehehean... Wh-What's wrohong?"
"Y-You really think I'm the best brother in the world?"
"Wh-" then Sam remembered, "Well, yeah..."
Then Dean smiled the widest Sam had ever seen in recent years. But he quickly changed his tune and went back to tickling Sam's underarms this time. Sam shrieked and laughed again.
"That was very sweet, Sammy, but I asked to be called the best prankster."
"Just say it and I promise I'll stop."
"HAHAHAHA YOUHUHU'RE THE BEHESTPRANKSTERINTHEWORLD NOW STAHAHAP, DEHEHEAN!"
"Hehe, thanks, bro."
And true to his word, Dean stopped his torture, leaving Sam lying there breathless and giggled, but best of all smiling.
"C-Can you please let me out now, King of Pranks?"
Dean chuckled and did as he was asked finally, much to the relief of Sam. When Sam sat up, he groaned and stretched out his sore limbs. His older brother sat next to him on the bed and ruffled his hair playfully.
"You're not such a bad brother either, Sam."
The younger Winchester grinned and looked up at Dean and murmured something Dean couldn't quite understand.
Sam looked away this time but said louder and clearer, "It's Sammy..."
Dean laughed and beamed as he threw an arm across his brother's shoulders, bringing him closer to him. And from that day and forevermore, he will be called Sammy Winchester.