Ethan didn't think much of it. Why would he? This wasn't the first time he and his sister Katie would be stuck at home for most of the summer holidays. Seasonal work was scarce, as this wasn't a touristy area, so neither of them managed to find jobs to help them pass the time. Not that they had been looking particularly hard. Their mother, being half-Asian and half-Slavic, frowned upon the very idea of teenagers working. In her view, they were supposed to focus on school: learning, passing exams, and getting to a good college. Everything else, she'd sometimes say, was merely a distraction.
To Ethan, it didn't make much sense at all, but he long since decided he wouldn't be the one to argue. Earning extra money wasn't high on his list of priorities, as the living standard of his family has been far from uncomfortable. A large house in an affluent neighborhood, with a expansive backyard and a sizeable swimming pool, wasn't exactly the worst holiday scenery. All of this, and more, was paid largely by his parents' divorce settlement, along with the alimony that his father has been dutifully sending them, every month for many years.
Ethan didn't resent the man. In fact, he didn't know him very well at all, given that the whole kerfuffle happened when he was around five or six years old. The cliche concept of his dad cheating on mom with the secretary had been totally abstract to him then. Now, it was just a distant memory. Since the divorce, Ethan's mom had done almost everything she could to ensure that neither him, nor his sister, would ever feel like the family was missing something -- or someone.
And so, being eighteen now, Ethan shouldn't have much to complain about. But in truth, he had, except his problems were all of personal nature. It would be an understatement to say that Ethan didn't have a lot of success navigating the social minefield of high school. Being quite shy, he didn't have a lot of friends. The few girls he managed to ask out, rather awkwardly, responded with casual dismissal at best and outright mockery at worst.
While he wasn't ugly by any means, and his 5'11" frame gave him some physical advantage, Ethan's biggest problem was the fact that he was thoroughly unremarkable. Other than try to pay attention to what the teachers were saying (with decent success, to be fair), his interests consisted primarily of playing video games and jerking off. As it turns out, this wasn't a winning combination when it came to attracting the opposite sex, so Ethan remained a virgin, with dim prospects for changing that anytime soon.
His summer plans thus revolved mostly around "practicing" those two hobbies. The presence of his sister Katie posed no risk of cramping his style, for he didn't have much of one to begin with. If anything, it was her who could complain about having to hang out with her dumpy brother.
In high school, Katie had been the furthest from a social outcast. It was impossible to be one when you were one of the hottest girls in class, and especially when you paired those good looks with a bubbly, easy-going personality. Topping off at 5'8", with trim and athletically toned body, she enjoyed plenty of attention from guys who wanted to get between her long legs, or place their groping hands on her perky breasts.
Quite a few of them succeeded, actually, because Katie had a rather casual approach to sex and dating. Spiteful girls would call her a slut, but the label didn't really stick to the cute, innocent-looking blonde. Sure, she might have had a new boyfriend every few weeks or so, but she never cheated on any of them, nor had drunken hook-ups at parties like some of her classmates did. Katie's mother instilled in her the importance of academic achievement, so that was always the girl's first priority.
Now, Katie was coming back after her first year in college, older and far more experienced than her brother Ethan. The taste of campus life still fresh in her mind, she was looking forward to several weeks in her quiet little hometown. Between reconnecting with her old friends (of both sexes), her plans included mostly sunbathing and chilling out by the pool.
So, for the first week or thereabouts, Katie has been relaxing under the bright California sun, scrolling through her phone and idly pondering whether to get in touch with some of the guys she used to date.
Today was no different, as she was just about ready to go downstairs and start soaking up the morning rays of sunshine. Already in her small bikini, she realized there was one more thing she needed to bring to enjoy another languid summer day.
"Ethan, did you take my sunscree-- Oh!"
Katie clearly should've knocked, instead of absentmindedly walking into her brother's room without warning. If she did, maybe she wouldn't have seen what she was looking at now, shocked and wide-eyed.
"Katie?!... What the hell?!"
Ethan froze. He was still in bed, although he had pushed the covers and exposed most of his naked body. Laying on his back, he had both hands wrapped around the long, turgid shaft of his impressive erection. Like every day since puberty hit him, he was taking care of his morning wood. The last thing he expected was for his always-sleeping-in sister to barge in at such an early hour without knocking!
"Huh..." she said quietly, a slight smirk curling her lips.
He blinked, realizing Katie hasn't apologized, or scurried away sheepishly. Instead, she was still standing in the doorway, with a rather quizzical expression on her face. A moment later, she giggled, then simply walked in and closed the door behind her.
"Ugh, what the fuck?..." Ethan groaned in confused embarrassment, finally reaching for the sheet to cover his nudity. "Get out! Can't you see I'm --"
"Busy jacking your big cock?" she finished for him with a grin, glancing meaningfully at the prominent flagpole that was now tenting the sheets. "Sorry, bro, I'm afraid I have seen it all! You might as well just keep going..."
Ethan felt like his brain has turned into scrambled eggs. He couldn't quite understand what his sister was even saying to him. "Wha... what?"
"Come on! There's nothing to be ashamed of," she insisted, a tip of her tongue appearing between her lips for a brief moment. "I can see you aren't exactly, you know, finished with this..."
Ethan let out something between a sigh and another embarrassed groan. "I know..."
"So?"
"I can't do it with you standing here!"
"Why not?" Katie asked teasingly. "I'm pretty sure it would only make it easier for you..."
Some of the color on Ethan's face suddenly drained away. "H-how do you mean?"
She stepped closer, crossing her arms under the skimpy bikini top. Her breasts swelled, barely covered by the tiny triangular patches that hid little more than her nipples. "You could have a closer look," she said in a low voice, "instead of just peeping out your window..."
He swallowed, hard. He knew there was no denying it, because he *had* been watching his sister sunbathing for the past week. While it wasn't always her scantily clad body that he thought about when touching his rock-hard dick, Ethan's sister was definitely a recurring star of his frequent stroke fantasies.
"I... I'm..."
