He'll need Kataras help (NSFW images)

Sokka didn't know what he expected... but he didn't expect this Avatar-thing to be so boring! He sat there for who knew how long, trying to get... something to happen. He almost dozed off once or twice there. But he certainly wasn't making any progress on this whole meditation-thing...

With a grunt, Sokka opened his eyes. The light from outside had dimmed and Katara had bundled back up in her furs again, though she was still watching him intently. "Not going so well?", his sister asked him, concerned for his success.

Sokka shook his head. "No... I don't know, there's just no way...", he admitted, though he was loathe to do so. The resulting look of disappointment on Kataras face only cemented it further. He had to do something to help him along again. He had to use his powers again. He had to use Katara again, but this time, he would make sure not to put her in any danger. Looking around the room, he saw no sign of their grandmother. "Where's Gran Gran?", Sokka asked.

"She was needed somewhere else. Might be a while until she's back. Do you want me to go get her?", Katara offered, ever helpful.

Again, Sokka shook his head. "No, it's fine. Don't think there's anything she can do...", he said. But now that he thought about it... there was something that Katara could help him with. Almost instantly, he formulated his next wish in his head:

'I wish that Katara would do whatever is necessary to help her brother become a better Avatar.'

Katara, who had no idea what her brother had just done or with what intentions, looked crestfallen. If their grandmother couldn't help him, what could she possibly have to offer Sokka in way of assistance. There was only one thing she could think of. "Oh. Should I just leave then? So you can have some peace and quiet?", she suggested quietly.

But that was the last thing Sokka wanted her to do. "I... I mean, there is something you can do.", he said while in his head, he made his second wish of the day:

'I wish that if Katara helps her brother cum, he'll manage to meditate.'

Kataras face lit up with joy. She could help him after all? "Yeah? What is it? Whatever it is, I'll-", she began, eagerly, sitting up from her bedding, furs sliding down her body when Sokka made his decision.

"Let me cum on your tits.", he cut her off.

A second of silence passed. Then another. Then one more. "What.", Katara asked flatly, blinking.

"I said I want to cum on your breasts, Katara.", Sokka repeated himself.

"WHAT!?", her scream rang out. Sokka had to hold his ears shut, this was the loudest he had ever heard his sister yell. But for good reason. Why would he... Katara couldn't believe what she had just heard. To even think of something like... like that! "Why would you say such a thing? What is... what is wrong with you? I'm your sister!", she protested, pulling her covers back up over her shoulders while she began blushing brightly, up to her ears.

"Nothing's wrong with me. It's not my fault! I'm a healthy man and you're the only girl around. I have needs, Katara...", he defended himself. He didn't want to go ahead and admit she had been his masturbation fantasy for the last two years, but it wouldn't take long for her to figure that out if she were to think about it.

Which she wasn't inclined to do right now. Or ever, for that matter. "W-Well... well, it's still wrong!", she argued weakly, flabbergasted at the mere suggestion that her brother saw her in a sexual way.

Sokka shrugged his shoulders at her protests. "Yeah, I know. But it's all I can think about right now. And it's not going to stop until I... until we do something about it.", he corrected himself and stood up, showing the growing bulge in his pants, causing Katara to shriek and hide her eyes behind a hand, while the other clung to her covers. "So... are you going to let me do it or not?", Sokka pressed her for an answer.

Katara didn't answer immediately. She let down her hand from her eyes and looked to one side of the room, then another, clearly contemplating what she should do. "Ugh! Why did my brother have to be the Avatar AND a total pervert?", she complained, causing Sokka to grin. Even if he didn't know she'd eventually agree, that was a good sign.

"Is that a yes or a no?", he pushed her even further.

Katara gritted her teeth and look at him angrily for a good long while before finally, she relented. "Argh, fine, FINE! But just this once, Sokka!", she insisted. Sokka knew this wouldn't be the last time, far from it. It would only be the first time.

Still, that didn't dampen his excitement when he saw his sister lower her covers and slowly pulled open her top, exposing her tits to him. "Th-there! That's good... right?", she asked, clearly embarrassed as she pointedly avoided looking at him while he got up and walked over to the side of her bed.

(Credit to the image goes to Anaxus)

Sokka took his sweet time admiring them as he slowly pulled his own pants down. They didn't look quite as amazing as he had always imagined them, but then again, he had always only ever seen Katara wear several layers of clothes, a necessity in this climate. Still, those were his sisters real tits and it made his erection only harder, knowing that he was the first man to ever see them in all their glory.

As his cock sprang free, Katara yelped a little and looked off to the side, eyes closed. "Just... just hurry up, alright? What if Gran Gran comes back?", she urged him on, clearly wanting to get this done with as quickly as possible.

The mental image of their grandmother was not what Sokka needed right now. But she was right... getting caught could cause a lot of trouble. "Yeah yeah, I know... why don't you push them up a bit...", he requested as he began stroking his cock, his throbbing length only a couple of inches away from his sisters tits.

And what tits they were. To his delight, Katara did as she was told, using her upper arms to squish her breasts together. "Like this?", she asked, innocently unaware of just how fired up Sokka was getting.

"Ah, yeah... wow, they're fantastic, Katara.", he complimented her and meant it. His strokes picked up in speed and urgency as he looked down at his sisters bountiful cleavage.

"Sh-shut up... are you getting closer?", she demanded to know, though she seemed at least ever so slightly pleased at the compliment.

Now, Sokka was enjoying himself immensely and Kataras protestations were actually quite a turn on for him. But he didn't want her to be constantly dreading having to do this in the future. Knowing that his sister loathed having to help him vent his lust would put quite a damper on it for him. So, he made one more wish:

'I wish that Katara secretly enjoys helping her brother this way.'

That little bit of knowledge combined with the fact that he noticed her rubbing her thighs together immediately after he made the wish caused Sokka to groan in pleasure. "Almost... look at me, Katara. I want you to look at me when I cum.", he told her and was rewarded with his baby sisters big blue eyes looking up at him. She looked angry and embarrassed, but the huge blush on her face was better than anything else.

It seemed that now Katara was catching on that her brother was getting close. "You better not get any in my hair, Sokka.", she warned him and only seconds later, Sokka came.

(Credit to the image goes to SunsetRiders7)

With a loud groan, Sokkas hips lurched forward. His first spurt shot out powerfully, higher than he had meant to, hitting Katara in her forehead. With a yelp, she leaned back, but couldn't escape the next few shots hitting her cheeks, mouth and chin, while the last few drops of Sokkas orgasm fell on their intended target, her tits.

While Sokka sighed contentedly, Katara, with an expression of pure disgust, wiped away a big glob of his cum from her cheek. "Eeeeewww! It's... it's everywhere! Ew, and it smells...", she complained as she reached for a bowl of water nearby and began washing her face and cleavage.

Meanwhile, Sokka pulled his pants back up and walked back to his bed. "Ahhh... that was great. Thanks a bunch, Katara.", he told her with a big, goofy grin, earning him a glare from his sister. She had missed a speck of his cum, near her ear. Sokka decided not to tell her.

Not that it'd improve Kataras mood one bit. "Just hurry up and meditate already! You said this'd help, so if it doesn't, I'll kick your butt.", she warned him.

"Hey now, don't put any more pressure on me, or you'll have to help me release it again.", he joked back, causing her to shut up but increase the intensity of her glaring tenfold. "Ah, I really do feel a lot lighter now. I think I'll manage now, just you wait and see, Katara.", he promised her and sat down, crosslegged, breathed in and out evenly and closed his eyes...