"Why Timmy, look at you," she teased as she reached down and began to softly stroke him through his boxers. "You're such a big boy, little brother! Something's got you all worked up! We're going to have to do something about that," she said, biting her lip as she smirked up at him and gave his cock a squeeze, causing it to twitch strongly in her hand.
Timmy reached under the bra hanging loosely off her chest, and Tammy gave a small gasp as his probing fingers brushed across her nipples, causing them to harden and her knees to go a bit weak. Now it was Timmy's turn to tease her: his left hand began to massage and pinch as his right slid down his sister's slim torso toward his ultimate goal, and he began to softly stroke her with his fingers as he backed her toward her bed. When her calves bumped against the bedframe, Timmy hooked his thumb through her panties, and with one smooth motion drew them down her legs as he pulled his own boxers down. His cock bounced out and nestled against her thigh, leaving a thin trail of precum on her skin as it throbbed intermittently against her.
She submissively allowed herself to be undressed by him, practically shaking with arousal and impatience as he slowly let her down onto the bed and pulled himself onto her.
"Why have we never done this before?" she asked breathlessly.
"I don't know," he responded, "but God you're the hottest woman I've ever seen."
She flushed in pleasure at the compliment, unaware that his unnatural lust for her body had been instilled by the light they had seen together. She, of course, had been unknowingly altered herself, filled with that same irresistible lust, and as her brother groped her willing body, driving his arousal and his need to thrust his sensitive dick into her fascinating pussy even higher, he finally pulled himself into position to penetrate her, and she realized that she had never wanted anything more. She opened herself to him, and instinctively began to push herself down onto him as soon as she felt contact. Her intense sexual arousal had thoroughly lubricated her young, fertile pussy, and he felt nothing but slick stimulation as his own instinct drove him to push himself into her tight, wet embrace.
Abruptly, however, he was briefly stopped by unexpected resistance. Far too inflamed with desire to hold back, he forcefully pushed himself further into her, feeling her flinch with momentary pain as he burst through her hymen, before she grabbed his hips and pulled him all the way in.
They stared into each other's wide-open eyes as he bottomed out deep inside her virginal pussy, both knowing that their relationship had changed forever, and definitely for the better. Somehow, the fact that they were related made the sex even hotter. As Timmy began to thrust himself in and out of his twin sister, he cupped and squeezed the small breasts that he now found so incredibly alluring, though he had never given them a second look until minutes before, and Tammy's tight pussy inexorably teased him closer and closer to his release. It wasn't long before the erotic idea and sensation of fucking his sibling became too much for Timmy, and the horny teenager found himself reflexively spurting himself into his twin sister's unprotected pussy. The stimulation of her brother's dick spasming inside her was more than Tammy could take, and her body too was overwhelmed by orgasm, the involuntary contractions of her pussy around her brother's still-jerking cock coaxing every last bit of his potent cum into her fertile vagina.
Finally, Timmy pulled himself out of his sister and lay down beside her, softly stroking her irresistible body, similar in so many ways to his own, while she massaged his deflating dick. As she looked at him with eyes full of sexual satisfaction, Timmy knew that he would never be as attracted to any other girl as he was to this one. She knew him better than anyone else ever would, and as his thoughts dwelt pleasantly on the closeness of their familial ties, he could already feel his arousal stirring once more at the thought of fucking her again. Tammy noticed the effect her body was having on her horny teenage brother, and fully embraced her sudden, welcome compulsion to swing over onto him and slide his hardening dick into her once more...
The next morning was a Saturday, and Michelle tended to sleep in on weekends. When she finally woke up and went out to make herself breakfast, the house was already empty, since her father usually worked a short shift during the day on Saturdays. She missed seeing him as she sat down to eat, but, remembering the interest he had expressed the night before in "getting back into the game", thought that maybe he'd get the chance to flirt with some pretty girls while he was out on patrol. Girls do love a guy in uniform, Michelle thought, an image of her dad standing tall and strong in his freshly-pressed uniform popping into her mind. Daddy's actually pretty ruggedly attractive for an older guy, she mused dreamily. She definitely saw what her mom had seen in him. Her hand drifted down to play with herself a bit, thinking of the strong arms that had held her as she grew into the woman she was today, but she didn't let herself get too distracted by her usual fantasizing about her father, because she was going over to Jim's house after breakfast, and didn't want to be even later than she already was.
Once she finally arrived at Jim's apartment the two of them sat down on the couch to watch a movie, but Michelle's leftover arousal from her short session with herself that morning soon drove her to begin rubbing her hand up and down his thigh, getting a bit closer to his cock each time as her libido flared back up. Jim clearly welcomed the attention, and eagerly leaned over to taste her soft lips. It wasn't long before she had climbed into his lap, and they quickly moved on to the heavy petting that had become the norm at this stage in their relationship.
As they continued to make out, however, Jim became more and more insistent, and Michelle could feel his cock growing erect against her leg. This might be the day! she thought excitedly, as he explored the tempting flesh further and further under her clothes, but soon she began to feel inexplicably reluctant, as though he wasn't the right one for her. She was still just as attracted to him as she'd always been, and her sexually aroused body still clearly wanted to feel his hard cock inside of her, but the two of them just didn't seem close enough, somehow. This was the same feeling of distance and isolation that she'd felt in all of her previous relationships, even though she had been certain that this time with Jim she'd finally left that part of her life behind her for good. Michelle wondered if she would feel differently if her first time had been with a brother or cousin, someone close to her who loved her, and who could show her the ropes in a safe, sexy family environment. Maybe then she wouldn't have sought out so many casual encounters in high school with boys who were just interested in her for her body.
Michelle thought more and more about how much she needed to have a close, familial connection with her lover, and soon came to the realization that she really didn't want to do this with Jim anymore, no matter how attracted to him she was or how turned on she was right now.
"I'm sorry Jim," she said as she abruptly got up off his lap. "Something about this just doesn't feel right. I think I need to go home, but I'll call you later."
Jim, ever the gentleman, expressed his understanding and sympathy, before watching sadly as the woman he thought he might love walked not just out of his apartment, but out of his life.
She was waiting for Dave when he arrived home that afternoon, lounging on the couch in boy shorts and a tight tank top. As he walked in the door, his attention was immediately drawn to the familiar, thrilling sight of the long pale legs, trim waist, and full breasts that he'd been fantasizing about all day during his patrol.
Michelle hopped off the couch with a youthful bounce in her step and skipped over to him, the glow of arousal in her face matching the damp spot readily visible on her pink panties. She pressed her hands into his broad chest and stood on tiptoes to reach up to him, the tips of her perky tits sliding up his torso in the process.
"Welcome home, Daddy," she whispered, leaning up to give him a slow, sensuous kiss on the lips that jumpstarted the bloodflow to his dick. "Were you able to get back in the game?" she asked flirtatiously, eyes sparkling with arousal as she rubbed her tits against his dress shirt.
She pressed her soft, curvy body up against his, and shivered in delight as she felt his hands exploring underneath her shirt, unimpeded by the bra that she'd decided to forego. She softly rubbed her crotch up and down the bulge she felt growing against it, while Dave pulled her shirt fully up as he began to gently grope and stroke his beloved daughter's large, soft breasts, neither of them realizing that their actions could be seen as anything out of the ordinary.