Hazell was sitting in front of the television with his baby sister sitting happilly on his lap. The siblings' parents have gone out for the evening, and left Hazell to take care of his sister Arie. He really didn't mind though, he loved spending time with his little sis, and the responsibility made him feel more grown-up. 
After they had gone out, the two felines had decided to put on a movie. Hazell let Arie choose, and she picked out one she must have seen about a hundred times: a pre-school age cartoon movie that promoted sharing and kindness. 
'Yawn,' thought Hazell, who was rather too old for movies like this. 'It's amazing, no matter how many times she watches this, she's still entertained by it,' he thought with a grin, seeing Arie's face light up with excitement.
After the movie finished, Arie rolled of her brother's lap to lay on the couch, and Hazell got up to get the movie from the VCR.
Hazell returned to the couch to join his little sis. "Okay Arie, what do you wanna do now?" He asked, as Arie moved over to snuggle against her brother.
"Oh!" Arie sat straight up with a start. "Big brother, I needa go pee, can you come with me?" she asked, tugging on Hazell's arm.
Hazell felt himself blush under his fur at his sister's request. "Um, yeah, of course. Let's go then." 
They got up and Arie led him into the bathroom. Quickly turning around  to give Arie her privacy as she dropped her shorts and climbed onto the toilet, Hazell looked at himself in the mirror. He thought he could see himself blushing through his white fur.
Arie started humming to herself softly, but was soon drowned out by the tinkling sound of the female feline relieving herself.
Hazell had a pang of guilt as he felt his boyhood start getting stiff in reaction to his baby sister going to the bathroom right next to him. 'Omigosh, this isn't right...' Hazell thought, feeling his cheeks blush hotter, trying to ignore the sound of Arie peeing and hoping that she can't see the front of his shorts bulging out. 'Not that she would understand what's happening if she did...' he thought with another pang of guilt.
"Do you need to pee also?" Arie piped up suddenly, evidently seeing that Hazell's hand had slid down to press against his growing stiffy, a movement that had been totally missed by Hazell.
His head turned quickly to Arie in a panic right as Arie was bending over to pull her shorts up, and caught the sight of her butt sticking out right at him. 
"Ah!" he exclaimed, quickly turning his head back to face himself in the mirror. "N-no, I'm okay, are you finished...?" He stammered, staring hard into the mirror. 
"Yup! Let's go back downstairs," she said as she marched right past Hazell, completely unaware that her brother was very uncomfortable with the large bulge pushing against his shorts. 
"Um, actually you go on ahead, I guess I do have to pee after all, haha..." he said back, trying to keep his voice from shaking. But if it did, it was lost on Arie, who just giggled and marched back down the stairs.
When Arie turned the corner at the bottom of the stairs, Hazell quickly shut the door and hastily moved in front of the toilet and dropped his shorts and underwear, letting his fully stiff boyhood free from the confining space. 
"Oh I shouldn't be doing this..." he muttered to himself, taking his stiff member in his hand and started pawing off. "Arie's my sister...this is SO wrong." But the image of Arie's exposed butt flashed across his mind, sending waves of curiosity and guilt through him. Try as he might, but Hazell was unable to keep his mind from imagining his sister fully naked. Having never seen her in that state before, it aroused his curiosity very much. 
Then with a jolt he remembered the last part of the instructions his mom had told him before they left. 'Remember Hazell,' she had said. 'Make sure Arie gets a bath before bed."
His imagination became filled with visions of Arie naked in the bathtub when, with a soft mewling sound, he squirt a thin stream of his young seed into the toilet.
Considerably more relaxed after his release, he quickly cleaned himself up, washed his hands and went back downstairs.
Right as he entered the living room, Arie attached herself to his arm. "Wha'cha wanna do now big brother?"
Looking into her bright, smiling face, made his insides squirm with anxiety at the task his mother had put him to. He glanced at the clock and saw that it was still fairly early.
"You hungry? How about we go make us some sandwiches?" Hazell suggested, needing something to do to take his mind off their trip to the bathroom.
After a dinner of peanut butter and jelly sandwiches, Arie wanted to play a boardgame. Hazell pulled down a rather old game of Chutes and Ladders. After Arie had beaten Hazell four times in a row, Hazell looked at the time again, and saw that Arie's bedtime was approaching. But first...
"I win again!" Arie said as she stuck her tongue out at her brother, who was looking rather anxious again. "Wanna play again?"
"No, um, it's time for your bath now," Hazell told his sister.
Arie's eyes opened wide in excitement at this news. "Ooo you're gonna give me a bath, Hazey?" Giggling at the use of the name she invented when she was first learning to talk.
'She always gives me that look when she uses that silly name...' he thought. 'Being all adorable like that isn't making me feel better about this.'
"Yup, Mom told me to give you a bath before bed," Hazell explained, as he led her sister back upstairs to the bathroom, who was obviously very excited.
Hazell went into Arie's bedroom to get some pajamas for her to change into after. He picked out a shirt and bottoms, and delicately put a pair of undies on top of the pile of clothes he was carrying, and returned to the bathroom.
He nearly dropped the clothes on to the floor in shock: Arie had decided to undress while Hazell had gone, and here she stood stark naked in front of  him, giving him a big smile.
Quickly dropping the clothes onto the counter, Hazell moved to the bathtub and turned on the faucet, trying to keep his eyes away from Arie's nakedness. A thought occured to him then. "Hey Arie, would you like bubbles?" He asked his sister without turning around. 'This way, she won't be completely visible with lots of bubbles,' he thought,
"Ooo okie, let's have bubbles!" She agreed happily.
Taking the bottle from under the sink and pouring  a portion of the soap solution into the water, immediatly the bath filled with bubbles.
Running over and testing the water with her paw, Arie called it good and stepped into the hot water and sank down to her neck with a soft murring sound.
"So how's the water feel,"? Hazell asked as he moved his eyes over the water, seeing if Arie's naked body was completely covered by the bubbles.
"Mmm it's really nice," She said closing her eyes. "Oh I know!" she sat bolt upright, lifting her bare chest out of the water. "You should get in with me too, Hazey!" she offered, while tugging on Hazell's arm.
Instantly the young cat's imagnation went wild at the thought of sharing a bath with his baby sister, only to be brought back to earth by the pressure he now felt in his pants of his boyhood becoming stiff again.
"Oh, um, no t-that's okay. Maybe another time though," he added seeing the disappointment on his sister face. "H-here, come closer so I can wash you."
Arie moved in front of her brother and sat up on her knees, so he could wash her back.
Taking a washcloth and a bar of soap, Hazell proceeded to bathe his little sister, starting first from her arms, down to her neck and shoulders. From there, he moved down her back and around to her chest.
When the kitten moved to give her brother her leg to be washed, just as he was running the washcloth over her knee, his eyes fell upon the young girl's sex, perfectly framed in a hole where no bubbles were.
Hazell let out an audible gasp and quickly looked away.
"What's wrong? Are you okay?" Arie asked with concern.
"Yeah, yeah, I'm okay...just got soap in my eyes," he invented wildly. 
But now his curiosity was piqued again. He knew he shouldn't look at his sister this way, but the growing pressure in his shorts was willing him to.
Tentitively taking the kitten's leg again, he made to be washing her leg extra carefully, then moved his eyes to take in the little cat's private parts. 
Though it was hard to tell through the water, she looked like she had a thin layer of very white fur, like the rest of her body and his own, and from the way her leg was lifted, her slit was spread open slightly, exposing light pink layers of her most sensitive flesh to the bewildered young boy.
Hazell dropped Arie's leg back into the water, feeling his stiffy aching for release. He forced himself to ignore his sexual urges, and he took Arie's other leg and washed it, glancing over at his baby sister's sex again, taking in all he dared. 'Though she must not even realize that that part of her is supposed to be kept private...' He thought, and his stiffy gave an excited squeeze.
After a quick shampooing, Hazell grabbed a towel wrapped it around Arie's waist, covering up her nakedness, to prevent himself from losing to his growing sexual urges. And after a brief drying-off, Hazell let Arie dress herself in the pajamas he brought, and they left the bathroom.
From there they entered Arie's bedroom. The young kitten hopped into bed eagerly, made sleepy from the warm bath. Hazell tucked his little sister in, said their 'good nights' and Arie fell asleep within minutes.
Once Hazell quietly shut Arie's door behind him, he ran back into the bathroom and shut the door. He bounded over to the toilet, dropped his pants and vigoriously pawed off his aching boyhood.
Purring loudly from the pleasure he had put off for so long, another thought came to him, and a goofy smile spread across his face. 'Maybe next time,' he thought. 'She'll let me touch her down there...'
And shortly after having this thought, his brain became clouded with ecstacy, and with much purring and mewling, he squirt off more of his seed than he'd ever done before.