Striptease

That last sentence caught Tim by surprise, so he just slumped to his back when Kari pushed on his shoulder. When she whipped the covers off the bed he came back to the here and now, but didn't know what to do to cover his embarrassment at the fact that Kari could obviously see the evidence of his erection against his boxers. Before he could think of what to say, she shocked him again by reaching into the fly, pulling his hard cock out, and sliding it into her mouth. He immediately came, and she dutifully swallowed every drop.

"I didn't realize it would be so quick", she said, with a somewhat disappointed look on her face. "I was too excited", he replied. He couldn't believe himself! He should be railing at her for what she just did, and chase her from his room. Instead he was making excuses for his sexual performance. "Well, it doesn't seem to have made much difference", she said, as she noticed the still-hard cock in her hand. She bent forward and drew it back into her mouth.

"Wait", said Tim. He knew he was decending into utter depravity, but he just couldn't stop himself. He reached down and slid off his boxers, then laid back again, naked under his baby sister's gaze, ready and willing to have her service him again. She did not immediately take him back into her mouth. Instead she studied his genitals, running her fingers through his pubic hair, and cupping and rolling his balls gently in her hand. Finally, she bent back down and sucked him back in. Her warm wet mouth and swirling tongue felt absolutely heavenly. Then a thought came to him. "How did you learn to do this?" he asked. Kari giggled. "Mandy and I have been practicing with hot dogs!" He didn't know how to respond, so he just laid back, closed his eyes, and enjoyed the sensations of his first real blow job.

He felt a perverse pride at the fact that he lasted much longer this time. Still, soon he could feel that familiar sensation. "I'm going to come!" Kari just picked up the tempo, and for the second time he filled her mouth with his jism. He drifted in ecstacy, and felt her lying back down beside him. He knew he owed her more, so he opened his eyes, slid over, and gave her a kiss. Then he put his hand behind her head and kissed her again, deeper, insistently, gently sliding his tongue between her lips. He had kissed a couple of girls before, but this time, kissing his kid sister, he found that for the first time he really meant it.

He sat up. "Now it's your turn!" He reached down and pulled her panties off. Her legs automatically drew apart, and he flopped down between them, staring at her pussy. He was surprised to see that she had nearly as much pubic hair as he did, although it was slightly lighter in color, and much softer and silkier compared to his tightly kinked curls. Suddenly, he realized he wasn't exactly sure what he was looking at. "Um, I've never actually seen a girl before, and well, uh ..." "Here, I'll show you!" Kari reached down and gave him a quick lesson in anatomy. She showed him her puffy outer lips, her flower-like inner lips, and her perky little clit. Then she pointed to the slot below her piss hole and said "Here is where you put your cock."

Where HE put HIS cock? He knew if he dwelt on her meaning he would get too nervous to do anything, so he just reached forward and began to roll her outer lips between his fingers, then moved his head up and did the same with his lips. He quickly realized that her moans meant pleasure, and not pain. He watched with interest as her outer lips began to part of their own accord, and the soft petals of her inner lips emerged. He played over them with the tip of his tongue and was rewarded with more moans and a quickening of her breath. He was surprised at how wet her entire pussy was becoming. He began to flick his tongue over her clit, and as her passion rose, he suddenly sucked it into his mouth, sucking furiously until she exploded with her pleasure.

Tim slid up his sister's body, intent on tasting her breasts. He licked all over them, and then sucked her left nipple into his mouth. He sucked hard, and Kari giggled. "I'm afraid you can suck as hard as you can, but you're not going to get anything out right now!" "What would I get out?" "Milk, of course." "Milk!!" "Obviously, someone hasn't been paying attention in Biology class!" Tim was too embarrassed at the truth of that to say anything, so he returned to his sucking. It was fun, and she seemed to enjoy it too.

"Kiss me!", Kari said suddenly. He slid up and complied, all too aware at the proximity this created between his cock and her pussy. He was unsure how to ask, but she took the decision away from him by grasping his erection in her hand and guiding the head into her pussy. Instinct took over and he thrust forward, but before he sank in very far his cock hit an obstruction. "Don't stop!" she said, "I know it will hurt a little, but I want it so badly! You're the only boy I've ever wanted to be my lover! Ever since I was a little girl I couldn't wait for my body to develop and prayed that my big brother Tim wouldn't find a girlfriend before he would start having sex with me!"

The emotions he felt when he heard this were so confusing that he just let instinct take over. On its own accord his body thrust forward, seeking its male genetic destiny to try to reproduce its kind. Her hymen resisted, then with a sudden tear it gave way and his cock plunged into her depths. He paused for a moment until he felt her relax, then he began to slowly start pumping his rod in and out of Kari's no longer virgin pussy.

I'm fucking! The thought shot through his mind. Just a few weeks ago he had been thinking that 16 was long enough to wait to start fucking girls. He knew he wanted it so badly, but was frightened at how to make it happen. He had a strange suspicion that if he asked a girl out on a date she might not be as eager to start fucking as he was. Even getting a girlfriend still meant he might have to wait weeks or even months! Yet here he was on his very birthday fucking a girl! The girl all his friends wanted, but that HE was fucking! The girl he had "helped" push in her stroller he thought as he thrust. The girl who had annoyed him by tagging along when he wanted to be with his friends he thought on the next thrust. The girl whose scraped knee he kissed to make it feel better when he taught her how to ride her new bike he thought as he thrust again. The little baby sister who his parents trusted to his care when they went away!

Look how I'm taking care of her - I'm fucking her brains out! Look Mom, I'm fucking your darling little girl until she won't be able to walk straight! Look Dad, I'm going to fill up your baby Kari with my semen, and maybe my baby! He knew he should feel guilty, but instead the sexual sensations felt great! He had a sneaking suspicion he was going to feel a lot different tomorrow, but for now his body was reveling in its introduction to manhood, and he could tell by every message that the sexy body beneath him was sending out that Kari felt exactly the same way. He felt his semen begin to rise and with one last thrust plunged his cock to the depths, pumping little Kari full of his sperm, pushing and pumping to try to get every last drop as deeply into her body as animally posssible. Finally, exhausted, he kissed her deeply then rolled off, lying on his back by her side. 

Already, his brain was starting to function again, and he knew they both had some very serious issues to confront. But for now he just laid back in sexual satisfaction, with Kari's sigh of pleasure all he needed to make him certain that at least on one, basic level, everything was just fine.