The prompt:
"Dean introduces Castiel to a lovely little thing called … sugar. Out of a dare, Sam wants Dean to find out how much it'll take until he's practically bouncing off the walls. It obviously takes a whole store to get him drunk. How much sugar will it take to get him hyper? Oh, and Gabriel lends a hand of course."

Dean has been distant and distracted lately. It didn't take a rocket scientist to figure that out. But the bigger question was why. Sam had a few hunches, but he couldn't really pinpoint the actual cause. Life for the Winchester boys had been normal... Well, as normal as their life could get... But there was one drastic change. A change that went by the name of Castiel; Dean's protector of an angel.

Once Castiel came onto the scene, Sam noticed an almost immediate change in Dean. He seemed... happier, if that was at all possible. Sure, he acted like Cas was a pain in his ass, and that Cas was causing him some kind of slow and painful death, but Sam knew better than that. Sam could see deeper. It was a familiar facade Dean put on to protect himself. Dean was raised to never show weakness, and, with the Winchesters' luck, happiness would lead to a weakness to be exploited. So, by Dean's logic, he could not be happy. Ever.

Still, Cas had sacrificed himself and then completely vanished, and Dean was out of it each time. It was only recently that Cas came back again "for good"... but he seemed different. Mix that with a different-acting Dean, and it was a bundle of awkward tension. Dean would never admit to have been missing Cas, or even being worried about him... So, instead, he kept his distance, with his cold, hard, emotionless mask in place.

So here they sit, Dean driving, Sam sitting in the passenger seat, awkward silence filling the space. It wasn't until a few hours into the trip that the idea came to Sam. "Dean, I have a challenge for you."

Dean's eyebrow perked, but his eyes never left the road. "A challenge?"

"Well... More like a bet, I guess."

He quickly glanced over at Sam. "Yeah? What's that?"

"You remember how it took the entire liquor store to get Cas drunk?"

Dean flinched at the mention of that name. "...Yes?"

"And you know how lots of sugar gets kids really hyper?"

"...Yeah?"

"Well... $50 says you can't get Cas hyper. Like, bouncing off the walls hyper."

Dean was silent. His eyes focused on the road.

They must have driven about 20 miles before Dean finally responded.

"How long do I have?"

"For what?"

"The bet, genius."

"As long as it takes."

"So, what, you'll give me $50 just to feed Cas sugar?"

"Whatever it takes to get him hyper. It's all fair game."

"And if I can't make him hyper, I owe you money?"

"That's the gist of it."

Dean pondered in silence for moment before finally surrendering, "You got yourself a deal."

A smug smile fell on Sam's face as they continued to drive in silence. Sam knew he got Dean's gears going now, and it would only be a matter of time before Dean and Cas were back to normal.

Dean walked out of the gas station with arms full of various brightly colored products and a cheesy grin plastered on his face. He walked up to the Impala, unable to open the door. He stared at Sam, who was sitting in the passenger seat still, until he got the hint to open the door for him.

"Geez, did you buy out the whole store?"

"You said whatever it takes."

"You realize that you probably spent more money on this stuff than you'll win, right?"

"Jokes on you, Sammy. It was your credit card."

Sam sighed and rolled his eyes. "Can we stop at a motel for the night? I'm sick of all this driving."

"Yeah, sure."

The Impala roared to life, and Dean drove the short distance to the nearest motel and made quick work of obtaining a room. He tossed the keys to Sam, and went back to the Impala to grab his sugary haul.

He walked into the room, and dumped the horde on the table, and began sorting. Energy drinks, candy bars, Pixy Stix, Skittles, Mt. Dew... You name it, Dean bought it.

"Don't judge me, Sammy. If I'm gonna do this, I'm gonna do this right."

"I said 'hyper.' Not 'kill him.'"

"Wait and see. I need to grab the rest from the car."

Sam heard a flutter of wings behind him, and a voice begin to speak. "You know sugar doesn't make people hyper, right? Especially angels."

Sam knew exactly who it was without even having to turn around. He could smell the chocolate on his breath. "Yeah, I know."

And now the sound of a candy wrapper crinkling. "Then what's going on?"

"An easy $50... And Dean and Cas need some bonding time. Win-win."

"Huh. You are tricky."

"Says the master."

"Flattery will get your everywhere."

"God damn it, Cas. Get back here!"

Dean was shouting at the spot where Cas was formerly standing, right before fluttering off.

Sam spoke up from the desk across the room, feeling bad for Cas. "Dean, you can't just shove Pixy Stix down his throat."

Dean turned towards Sam, almost defensively. "Hey, you said whatever it takes. This is what it takes."

Sam just shook his head in disbelief. "Dean, you gotta be nicer to him if you expect him to cooperate."

Dean grumbled and cursed under his breath, and changed his tone drastically. "Dearest Castiel. If you are able to, and it works with your schedule, could you maybe, perhaps, come here, please?"

A flutter of wings sounded behind him.

Sam leaned back in his chair, a smug look of satisfaction etched into his face. "See, Dean? Was that so hard?"

Dean just glared at Sam, giving him his answer.

"You called, Dean?"

"Cas, close your eyes and open your mouth."

"I don't understand."

"Close your eyes. Open your mouth."

Castiel just stared defiantly at Dean, tilting his head to the side.

"Cas, you're killing me... Look, it's good!"

Dean tiled his head back, and poured half of a Pixy Stix in his mouth. He shuddered a little as the sweet-sour flavor raped his tastebuds.

"There. Om nom nom, so good. Now, open up."

"Why?"

"Shut up, and open your mouth."

Cas closed his eyes and opened his mouth. Dean walked forward and poured about 4 Pixy Stix into Cas' mouth.

"Okay, let it dissolve a bit, and then swallow."

Dean watched Cas swallow, and there was a few minutes of awkward, tension-filled silence.

"Anything?"

"May I open my eyes now?"

"No. Open your mouth again."

Castiel did, and another 4 Pixy Stix were poured in. Cas swallowed.

"Anything yet?"

"I don't understand-"

"Damn it."

Dean walked over to the table 'o treats, and grabbed a can of Mt. Dew. He pulled it open, and marched back over to Cas.

"Drink this."

"Dean..."

"Just drink it. It's good for your vessel."

Cas began to drink the sugary drink. He apparently liked it, because he guzzled the entire can in about 30 seconds.

Cas glanced up at Dean with a glazed-over look in his eyes.

"Hey... You okay?"

"Yes."

"You sure? You don't look very well."

"I am fine."

"Here, sit down for a while."

Dean ushered Cas to the nearby bed, and sat him down on the edge. He took a seat on the opposite side of the bed, and slumped in defeat.

Dean must have fallen asleep, because he was woken by a loud giggle.

"What the hell?"

He looked around the tiny motel room, and didn't notice anything out of the ordinary. Sam was typing away at his laptop, and Cas was sitting where Dean left him. But Sam must have noticed the giggle, too, because he looked up in confusion.

"What was that?" Sam asked in confusion.

Dean arched an eyebrow. "That wasn't you?"

Sam narrowed his eyes. "When have I ever giggled?"

"You giggle when you watch funny cat videos on your facetube or whatever."

"What? Do not!"

"I can hear you at night.!"

"Whatever, Dean."

Their little fight was broken up by what sounded like a cellphone vibrating.

"Dude... Was that your phone?"

"My phone isn't on vibrate."

"Mine either."

The vibration sound got louder, and the bed Dean was laying in began to shake.

"What the hell?" Sam stood up, walking over to the bed.

"Oh my god, it's like Magic Fingers." Dean let out a little moan.

"Dude, this isn't one of those beds."

Dean lifted his head, but didn't bother getting out of the bed. "Then what's going on?"

Sam walked to the other side of the bed, and stared at Cas. "I think... I think it's Castiel."

"What?"

"Look."

Dean put a hand on Cas' back, and, sure enough, he was vibrating.

"It worked!"

"This doesn't count. He isn't hyper. He's just... vibrating."

Castiel looked up at Sam, his eyes glazed over, and darted out his hand, running it through Sam's hair. He let out a giggle.

Dean looked over at the scene with a smirk on his face. "This isn't hyper?"

Sam slapped Cas' hand away, but Cas went back for his hair, giggling more.

Sam was in a state of disbelief. "What's wrong with you, Cas?"

Cas just giggled. "Soft."

"Ready to give me that 50 bucks yet?"

"No. This isn't possible."

"What? Scared to lose?"

"No, it's not that..."

Cas continued to giggle, and started to poke Sam's arm.

"Stop touching me, Cas."

"I'm not touching you."

Sam glared over at Dean, with a look of exasperation in his eyes. "Dean. Control your angel."

Dean shrugged. "He's not my angel."

Cas started poking him more.

Sam started grinding his teeth. "Stop, Cas."

Cas giggled. "Stop what?"

"Touching me," he growled out.

Cas giggled some more and shook his head defiantly. "No."

Sam tried to grab Castiel's wrist, but the angel vanished before he could grab hold. A flutter of wings, and Castiel appeared next to Dean and started petting his face whilst giggling.

Dean looked up at Cas, dumbfounded. "Wait, you made the bed stop... That felt good."

Cas vanished again and reappeared behind Sam, shoving him forward onto the bed just in time to vanish again next to the table 'o treats.

"Oh boy..."

"Stop him, Dean."

Dean had a smile on his face. "No way. This is too much fun."

Cas grabbed a bag of Skittles and ripped them open, pouring the entire package into his mouth, chewing wildly... streams of rainbow-colored drool coming down his chin. Then he worked towards the case of the Mt. Dew and downed another can.

Dean laid on the bed, head propped up on his arm, watching the madness ensue with a cheesy grin on his face. Sam stared on in disbelief.

Cas vanished again in a poof, and reappeared on the bed next to Sam and Dean, vibrating the bed. Dean laid back, moaning in pleasure, and Cas took the moment to flick Sam in the ear before vanishing again.

"This. Isn't. Possible."

"Aww, where'd you go?" Dean looked around, pouting.

"Dean, don't you get it? This isn't possible!"

"Well, it's happening. I believe you owe me $50."

"No, Dean. You are cheating somehow."

"What? How am I cheating? I just fed him some sugar... and look at him go now."

Cas appeared next to the table again, tearing into a Snickers, giggling the entire time.

"Dean. Sugar doesn't make people hyper."

"He's not people. He's an angel."

"It doesn't make angels hyper, either. Just look at Gabriel." Sam had a light bulb moment, and narrowed his eyes. "Gabriel..."

Another flutter of wings, and the tricky man appeared next to Castiel, munching on a candy bar of his own. "You called?"

Sam pointed at Cas. "Is this your doing?"

Gabriel feigned a look of general surprise. "What, me? No way!"

"This has your name written all over it."

Castiel vanished and reappeared next to Dean on the bed, apparently crashing from the sugar high... His eyes started drooping, and he curled into a ball next to Dean.

"Aww," Dean said, "Poor little guy tuckered himself out."

Gabriel snapped his fingers, and Castiel instantly snapped out of it, sitting up, and looking confused.

Sam narrowed his eyes once again. "So, was that a yes?"

Gabriel ignored him, continuing to munch on his Snickers. "I believe you owe your brother some money."

"What? No. Not 'til you admit to rigging this whole thing."

Gabriel rolled his eyes. "Fine. I may have... helped."

Sam crossed his arms. "Helped?"

Gabriel sighed in defeat. "Fine. I did it. Happy now?"

Dean chimed in from the bed. "You're a pain in the ass, you know that?"

Gabriel stuck up his hands defensively. "Hey, just giving your darling brother his just deserts. He can't be tricking people around here. That's my job."

Dean stared at Gabriel. "He was trying to trick me?"

"Yes, Dean." Gabriel turned to Sam, motioning towards Dean. "You know, this guy is really slow on the uptake."

Cas blinked in confusion. "What is happening."

Dean patted him on the shoulder, "Nothing, Cas. Sam was just going to give me $50, and then I was going to go to a bar."

Sam sighed, and pulled out his wallet. He grabbed a $50 bill and crumpled it up, then threw it at Dean. "Take Cas with you. You need a babysitter."