Rita's glare intensified as a slow, arrogant smile spread over her brother's face. She couldn't believe that the little dweeb had actually gotten the better of her for once.

She knew that getting a tattoo was a bad move - with parents as strict as hers, even suggesting that she was thinking about getting inked would have been enough to get her grounded for life, but one rebellious night, she'd told herself that it was her life to live, and gotten a butterfly on the inside of her thigh - somewhere that her parents would never, ever see.

If it were anything else, she'd just be able to claim that her brother was lying, or somehow distract them, but she knew that all he had to do was drop a hint of an idea, and her parents would insist that they prove him wrong.

He had her exactly where he wanted her.

"It's simple," Fergus said. "If you don't want mom and dad seeing it, you have to show me your tits."

"What!? But ... I'm your sister!"

"I've never seen any before," the eighteen-year old replied, and before Rita could splutteringly object, he gestured at her leg.

Rita had no idea how he'd even caught a glimpse of her tattoo in the first place, but his request seemed to suggest that he had more than a sisterly interest in her. She shuddered at the idea of him jerking off at the sight of her tits ... but he had left her with no choice.

There was a long pause, as Rita considered whether spending the rest of her life under direct parental supervision was better or worse than her creep of a brother seeing her topless. Finally, through gritted teeth, she tersely gave a single-word response.

"Fine."

"Once a day," he nonchalantly added. "For the next two weeks."

"Fine!" Rita responded, and pulled her shirt up.

Better to get this over with. The first time, she knew, would be the worst. Reaching around to undo her bra, she hoped that he'd get bored of them quickly.

By the smirk on his face as her bra dropped and her nipples came into view, she didn't think it was likely.

"What!?" Rita said angrily, her lips pursed and one foot stomping the ground. "But we had a deal!"

"I'm sorry," her brother replied calmly, "but the deal was once a day for two weeks. No more, no less."

It had just hit 10pm - like clockwork, the sound of snoring had emerged from their parent's room, and just as she had for the past fourteen nights, Rita had sneaked over to flash Fergus.

Tonight, however, he'd reminded her that the two weeks were up. No matter how much she'd begged or pleaded, his trademark stubbornness had remained in place, and he'd refused to let her show him his tits again.

"Come on, bro..." Rita said desperately. "Let's talk about this..."

"I'll tell you what..." Fergus replied, deliberately slowly. "Show me your pussy as well, and I'll let you flash me."

Rita instinctively recoiled, and her brother looked worried for a second, before his smirk returned, and he looked directly between her legs.

Glad she was wearing jeans, Rita tried another tack.

"How about chores? Let me keep on showing you my tits, and I'll do your chores for the next week ... the next month!"

"I'm sorry," Fergus said, turning back to his computer. "I made an offer. Show me your pussy, and I'll let you show me your tits. Actually, just so that I'm definitely getting my money's worth, your ass as well."

"But..." Rita replied, feeling sick at the idea, " ... but I'd pretty much be naked!"

"Perfect," Fergus said, taking her statement as an agreement. "Once a night, but naked, instead of just topless. Starting tonight, of course."

Rita bit her lip nervously ... she'd had a few boyfriends, of course, but none of them had actually seen her naked body before. Ignoring the ick-factor of being naked in front of her fully-clothed brother - in his bedroom, at that - she felt extremely self-conscious.

But compared to not being allowed to flash Fergus any more...

Almost immediately, she started peeling off the tight sweater she'd worn in. It's not that much worse than being topless, after all she told herself, and after removing her bra, she slowly unbuttoned her jeans, and lowered them as well.

As Fergus watched expectantly, she hooked her fingers into the elastic of her panties, and reluctantly dragged them down her legs, showing off her neatly-trimmed pussy.

The broad smile on Fergus's face showed that he was enjoying the view. She shuffled nervously on the spot, as he leaned in close, staring at her pussy, not even noticing the breasts that she was proudly thrusting forward.

Before too long, he dismissed her. Rita had a fairly good idea of what he was going to do immediately after she left.

"Would it really be so bad?"

"Of course!"

Rita couldn't even believe that he'd ask. She was his sister, for Christ's sake. Other than the fact that she came into his room each night, and stripped for his viewing pleasure, there was absolutely nothing weird about their relationship ... where did he get the idea that it was okay to ask her to ... to ... to do THAT!

"Well then, I'm just going to go to sleep. Good night, Rita."

Fergus turned away, and as Rita considered the possibility of leaving without him even getting a peek of her pussy, she reconsidered.

That night, she'd gone into his room as usual, to stand in front of him and slowly strip. She loved the way that he stared at her, his heavy breathing as she removed her panties, the erotic thrill of knowing that her body was being admired ... to suddenly cut her off from the highlight of her day was ... well, it was just plain cruel.

"Oh, hey sis. Sorry, I don't feel like jerking off tonight," he'd said dismissively as she entered. "Maybe tomorrow."

Her throat suddenly closed with panic, and it wasn't until he'd turned back to his computer and started typing that she found her voice again.

"What? You ... you can't do that."

"Sure I can," he said, not even turning back to face her. "It's my room."

"Yeah, but ... that's not fair! How about if I strip and you just don't jerk off?"

"Sorry, Rita. There's only one reason I look at you each night, and I think you know it. Of course..."

He'd turned back to her, and her hopes had risen, only to be dashed again by his next words.

"Maybe if ... maybe if you jerked me off. Yeah! If you jerk me off, I'll let you get naked for me."

What a pervert. What a sick, foul, disgusting human begin. What a horrible request ... looking at each other, that was fine. Everyone saw their siblings naked from time to time, after all. But jerking him off? That was crossing a line that she knew she could never cross.

"Never!" she'd said, and there had been a long pause, before he'd asked her if it would really be so bad. Now, as she stared at his disinterested back, she was asking herself the same thing.

"It's my body," she feebly protested. "If I decide I want to show you my body, it's my right. You can't just refuse it."

"G'night, Rita..." he said, and she'd sighed and agreed.

His arrogant smirk was back as he turned around, and undid his pants. He didn't even have the decency to stand up, and after disrobing, Rita got down on her knees in front of him.

"Let me know when you're going to cum, you little twerp" she said, making sure to aim away from her body.

"Oh come on," he replied. "If you're going to jerk me off, you at least have to let me cum on your body. If you're not careful, I might not be in the mood tomorrow night either..."

Rita gagged at the idea of feeling her brother's hot, sticky cum landing on her body, but she knew that he was holding all the cards. A part of her wished that she hadn't spent so much time convincing him to let her strip for him in the first place, but now that she'd started, she knew that she'd do anything to avoid giving it up.

"Seriously?" she asked, looking up at him, trying to use her big eyes to her advantage, to make him realize just how wrong what he was asking her to do was.

In return, she just got a smirk, and so with a sigh she reached out, wrapped her hand around his stiff prick, and started to jerk him off.

"You'd better have a towel handy..." she muttered, wishing she didn't get quite so much pride at the hungry look that came into his eyes as he stared at her naked body kneeling before him.

That first night he aimed for her tits, but ended up hitting her face as well.

The pause stretched out for an unbearably long time, the two siblings locked in a death-stare.

Fergus's ever-present smirk was on his face, as Rita stood before him, completely naked and close to crying with frustration.

Fergus had just told her that he was thinking of dating a girl at school, and wanted to "save himself up" for her. The prospect of going even a single night without being doused in her brother's cum scared Rita so much that she'd responded without thinking, threatening to never let him see her tits again.

Even Rita knew that she'd gone too far with that one, and the pair were sitting in silence as they each waited for the other to break.