FOR THE PURISTS: This is an incest story, but it is also an exhibitionist/voyeur story and hence, not hardcore sex.
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Gavin shouldn't have been sexually frustrated, but there was no ignoring it. Even just 18, almost 19 years old and only recently introduced to the wild world of casual sex, there were numerous women he could have called up at any moment to satisfy his cravings. But tonight he didn't even have the motivation to pick up a phone. Having lots of casual sex had drawbacks, which was becoming painfully clear. He and his girlfriend hadn't spoken in weeks, and he wasn't sure why. But now he had found himself with very strong feelings for her older sister, and that hurt any chance he had of finding the right way to approach the situation.
He wanted to be alone tonight--well, not wanted as much as needed. He had been in his room, the door shut and the lights off, for hours now, just thinking. And as he sat and thought about his problems, he stared out his window, toward the neighbor's house. Waiting. Anticipating.
Gavin had perhaps the greatest view ever conceived through that window. It was the view of his neighbor's window, a window of a bedroom where the shades were usually up, and the person living in that bedroom was hands-down the most beautiful, erotic, physically perfect 18 year old redhead on Earth. And she loved to put on shows for him.
It had been a while since he'd seen a show, because when you're forced to choose between staying home and watching the world's sexiest young woman strip through your window and going out to fuck any of several very hot and horny women who were always blowing his mind, 9 times out of 10 Gavin was going to choose fucking. But Autumn--that was her name--was special enough that she was still worth taking a night off from real sex and simply enjoying a visual performance.
So far, her room had been empty. The good news was that the shades were up in Autumn's room, and the lights were all on. He knew she was home, and as soon as she came in, he'd be able to see everything. He was already prepared; sitting in his chair in the nude, his dick soft but ready. He considered even giving her a show, as he sometimes did, but tonight he really just needed to get off, and was in a rare, selfish mood.
Besides, there was something else.
Gavin lived with his sister, Alana. She lived in their late parent's basement, while he had the bulk of the main floor to himself. It offered great privacy, and tonight that meant enough privacy for Alana to have come home and not even know Gavin was still there. He had heard her enter the house and call his name to say hi, but he hadn't responded. She called again, coming down the hall to his door, but he didn't say a word. He wasn't sure what he was going to say for himself if she actually opened his door and stepped in, seeing him naked, but fortunately she only knocked before giving up.
Or maybe that was unfortunate. Gavin was attracted to his sister on many levels, and though he had tried to forget about what had happened between them in the past, he just couldn't let it go. If Autumn was the perfect physical specimen of feminine beauty, Alana was the first runner-up, and each time Gavin saw her, she seemed to be gaining. She was a blue-eyed blonde, athletic but with a soft body, an ass that sent men to their knees and a spectacular pair of large, firm, shapely breasts. She had a face everyone instantly fell in love with, and a smile that could turn your whole life around. She seemed to radiate the experience and maturity of someone older, but had the irresistible energy of someone who had yet to face the harsh realities of life.
Though she was 26 to his 18 years of age, and therefore they had never been in high school together, he knew her type: she had been the unbearably hot girl who was friends with everyone, but didn't get too friendly with anyone, which only increased her appeal. While by no means a saint, Alana had only recently come out of her shell, revealing a sexual beast that surprised even her. Gavin had witnessed her that way firsthand, which would've been bad enough if he hadn't been attracted to her already.
Alana was so much, and there was one more thing; she was bisexual. Or maybe a lesbian. Gavin wasn't sure she had even decided yet. Her attraction to women was a new thing she'd been exploring, and at least part of her considered she might be really be inclined to switch to only women. Gavin had his doubts about that, but he couldn't deny she was at least bisexual. After she left his door upon getting no response, she went downstairs, showered and changed, then went out for the night. He hadn't heard her start her car, and so he guessed where she was going.
And that was really why he was sitting naked in his chair, watching Autumn's window. It was when he spotted Alana with Autumn that Gavin had first discovered his sister's new sexuality. In fact, he had jerked off to the sight of his sister and Autumn 69ing each other through this very same window. Though he didn't know it was his sister for a few more days, Gavin knew now. He was sure Alana was going to see Autumn tonight, and so he waited, his dick stirring at the thought.
As far as he knew, Autumn hadn't changed yet, and so maybe she would be coming into her room to do this now. Maybe his sister would be in the room as she did it, watching and getting off on it, just like he would. After all, Alana didn't think Gavin was home, so there would be no reason for her to want to shut blinds.