Another addition to Dalma22's Ticklefic mission.I included a little emotional h/c because I can't help myself. Don't own anything BTR. And yes, I grew up with big brothers.

Kendall startled as the first drop of water hit his forehead. Loath to open his eyes, he wished the summer sprinkle away. He was far too comfortable, spread out on his striped picnic blanket in Palm Woods Park, to even consider moving. Another drip splashed on his brow, and another. Scrunching his eyes tighter he shook his head, hoping to flick the offending rain away. But the flow only increased, dribbling now over his forehead, reaching his hairline, running into his eyes and down his nose and to his mouth until he lurched upright, sputtering, to find he was not in the park at all.

"Katie!" Had he been functionally awake the protest would have carried more threat, but the force was lost by the groggy break in his voice. He pushed his wet bangs back over his head and wiped his face with the sleeve of his tee. Gah, there was water in his ears. "What'd you do that for?"

His sister stood by his bed, coolly observant, a cup of water in hand. "You needed to wake up," she said simply, using the tone Kendall dubbed as her "infuriatingly superior" voice.

"There are other ways to wake a guy!" Kendall stripped the wet pillowcase from the pillow which, happily, was mostly dry.

"You weren't responding to voice and shoves, and this cup was right here," Katie shrugged. Kendall cocked his head, shooting her a sideways glance. The words sounded like her usual "I-own-you" quips, but something was off. The tone didn't match. There was no gloating "you-lose-I-win" victory in her voice. (And yes, he did describe most of Katie's characteristics in hyphenated quotes, thank you. You try finding a single adjective for each one.)

He dipped his fingers in the cup and flicked water at her before she could back away. "So why did I have to wake up?" he whined. "What time is it?"

"It's 10, lazybutt. Everyone else has already gone out."

Kendall was ready to ask again what this had to do with him having to be up, when he noticed that Katie was still in her pajamas, and pieced that together with the fact that she'd allowed everyone to leave without tagging along. Now he knew why she was standing in his room, waking him up, instead of taking advantage of unchallenged TV and gaming time. And he knew what he had to do.

"Lazybutt?!" He lunged at his sister, tackled her to the foot of the bed, and began to tickle her unmercifully. "Meet Ticklebutt!" He poked at her sides as she squealed and wriggled, unable to control her giggles.

"Kendall! St- stop!"

"Who's," poke "gonna" poke "make me? My shrimp of a sis?" poke poke "Oh wait, maybe it's time for some water payback!" Kendall reached for the water cup on the nightstand. Taking advantage of his distraction, Katie curled into a protective ball, but promptly fell off the bed, causing a fit of laughter from both of them. Kendall loomed over her, a foot on each side preventing her escape, tipping, tipping, tipping the cup just short of pouring.

"No!" she yelped, hands covering her face.

"What, I don't get revenge?"

"No!" She was hiccupping between protests as he knelt next to her, tickling again till her hands moved to protect her ribs.

"Oops." A dribble of water hit Katie's undefended face.

"Kendall!"

"You know how to stop it."

"No!"

"All right then..." He dribbled more water, hitting her nose.

"Uh-uh, I won't!"

"Fine with me. Lotta water left in here. Oops. Oops. Oops." She had her hands back at her face, so he aimed for her hair. When she managed to turn herself over, he dribbled it on her ear.

"Augh! You are the worse big brother ever!"

"Those aren't the magic words," he scolded. "I'll give you one more chance, because I'm awesome like that."

"No!"

He set down the cup and resumed full-time tickling. "I know your limits, little sis. Come on now."

Katie kicked out and Kendall grabbed her foot, starting in on her sole, her absolutely most ticklish spot.

"OK!" It was her highest pitch, and signal to both of them that she was defeated.

"What?" He continued to torture her as she tried to pull out of his grasp.

"O - K!"

"OK what?"

"Kendall… rules!"

"What?"

"Kendall rules." She slumped into the carpet.

"Bam!" Kendall stood up, preening. "Yes I do."

He reached down, hauling Katie to her feet, and sat expectantly on the edge of the bed. Sure enough, the big brown eyes began to water. He pulled her into a hug, as familiar as breathing, and felt her let loose. His own eyes prickled as she did. It had been his job, for 10 years, to protect her. To move objects out of her way as she crawled. To hover anxiously when she walked. To run alongside as she learned to ride a bike. To chase away her nightmares when Mom was working late and he was in charge. To know when something was hurting her. Now he stroked her hair, his invincible 10-year-old sister. "Aw, Katie."

She slowed down to hitched breaths and snuffled loudly.

"Ew."

Katie snorted and hugged him tighter, hiding her face for another moment. "It's just hard some days," she finally whispered. "You know?"

"I know."

"You see these perfect families on TV, doofus dads with their kids."

"Doofus is a good word for it."

She gave a snort and another sniffle. "It's just some days, I wonder…" she looked up at him and the tears were welling in her eyes again "…why he left us."

Kendall felt the unwelcome lump in his throat, from all the times he'd asked himself the same question.

"It wasn't because of us, Katie." He tugged on a braid and met her eyes, reciting his own mantra. "It was because he was a jerk, and he hurt Mom, and we're happy and much better off without him." He gave her an extra squeeze and kissed her forehead. "Besides, you have me, and I rule."

It was another 30 seconds before Katie nodded and straightened up, wiping her eyes with blowing out a breath. Composed, she jabbed his chest with her finger. "You," and there was the familiar threatening tone, "don't tell anyone."

"That you're ridiculously ticklish?" Kendall jabbed at her but she danced out of the way. "Sorry, but that cat's out of the bag. And now, I'm gonna kick your butt at Castlebashers."

Katie bolted out of the room. "I get the platinum controller!"

"Yeah, all right, this time!" he called as he followed her. "Because I rule!"

A/N The prompt was "write a Kendall-Katie sibling fic where Kendall (16) tickles Katie (10) for waking him up by pouring a glass of cold water on his face."