Borderline

June 14th was a special night for Melissa and Mark. It was two days before the twins' birthday. Born mere seconds apart, the Gemini's had been close for as long as they lived. Perhaps it was their nature as twins, but they had felt intimate forever. As infants, one would throw a tantrum if the other were removed from the room.

Mark felt that separation now. He awoke, sure of the feeling that Melissa was awake as well. He glanced around the room. Melissa was not there. He sighed. That was because she had her own room now. It wasn't appropriate for teens of their age to share a room anymore. That's what their parents had said, anyway. They could never understand the bond between the two. Mark had never felt uncomfortable with Melissa in his entire life.

He removed the sheet that was covering his body, and got up. He knew where she was.

Melissa was lying on the roof of the house. The heat from the sunlight of the day kept the black shingles that coated the roof warm long into the night. She lay on one of the soft towels that she loved, with her hands behind her head as she gazed at the stars. She sighed. Mark would be showing up soon.

As if on cue, Mark poked his head out of the window that opened to the roof. "Hey," he said softly.

"Hey," she answered.

Mark stepped through the window and stopped a minute to gaze at his lovely twin sister. They were quite a mixed up pair of twins. She had nice white skin of cream; he got a tan going out to get the mail. The black of the roof just accentuated the paleness of her skin. Melissa was a swimmer, and her body's tone reflected it. Her nightshirt flowed gently over her ample B cup breasts. Her long, muscled legs led up to soft, womanly hips. Hips that her nightshirt barely covered, to Mark's delight. He quietly told her, "I like that nightshirt."

She giggled. "I hate those shorts," she answered, not looking at him. She didn't have to see him to know what he was wearing, but she looked anyway. Her brother had had a pair of sweatpants that he refused to throw out, and when they finally became ripped, he cut them into a pair of shorts. That was all he was wearing. She knew that he usually slept naked, and he had put them on to come talk to her. It was purely cosmetic, as she had seen him naked many times before. She smiled as she remembered the first time.

It was seven years ago, now. On a weekend, she had jumped on his bed, to wake him up. Startled, he hadn't had the time to react when she pulled down the sheets. She had gotten the shock of her life when she saw there was nothing on him. Even more surprising, his cock was stiff as a rod, something she had heard about, but never seen. He started to sputter things out, but she silenced him with a finger on his mouth.

"It's ok," she had said. "You showed me yours, so I'll show you mine!"

Then, with a giggle, she started to remove her nightshirt…

That had been a fun day. Now, his body was like a sculptor's dream. His 180-pound frame made the muscle that he had stand out. Despite that rich tone, he wasn't an athlete—he left that to his sister. He was in good shape for the sake of being in good shape.

"Mind if I lay next to you?" he asked.

"Pull up a shingle," she laughed in reply.

He sat down beside her, and then lay back, with his arms behind his head, just like her. His elbows playfully bumped against hers, and they shoved them against each other for a few seconds. The height difference between them was apparent, as his feet were several inches down from hers.

"Whatcha thinkin' about?" he asked.

"You know what!" she said.

"Yep," he sighed. "Two days."

"Two days," she repeated.

All those years ago, when they had realized that their intimate feelings for each other were something special, they had made a pact. A pact that they wouldn't fulfill those feelings until they had turned eighteen. They had agreed that those feelings would build up until they finally boiled over. In the meantime, they had learned each other's bodies as intimately as they knew their own.

"Are you excited?" she asked.

"Uh, yeah!" he blurted.

Melissa reached over and put her left hand on Mark's waist. "Me too," she whispered.

She gently began to stroke the quickly hardening package in his shorts. He shuddered and sighed softly. Other girls had run their hands over his naked penis before, but they never got the same reaction from him as his sister could bring. Her touch had a current of electricity in it. He believed that it came from the intimate bond between them. She could touch his cock through layers of clothes and still make him cum, and he could do the same to her. It was part of their intimacy that each knew exactly what the other liked.

He draped his right leg over her left one and then intertwined the two of them. She moaned softly. He knew very well that she loved to feel his leg hair tickling her smooth, pale skin. As a reward, she gently palmed his balls through his shorts, making him gasp.

"You're going to make me come," he exclaimed.

"I know," she giggled.

He struggled to not concentrate solely on the feelings of his building orgasm. The scent of his sister's rich pussy juice intoxicated him, and he knew that she must be so wet that it was literally dripping out of her. And that meant she was extremely horny.

It was time to race. As brother and sister, both of them were extremely competitive with each other. This was a pattern they had fallen into a long time ago. She would begin to stroke him, and he would wrap his leg around hers. When he could tell she was horny enough, he'd start to finger her. They would then being to masturbate each other to see who came first. The reward for winning was getting to come on the other person. They both knew Melissa currently had a six-come winning streak- she was a very determined girl. She loved forcing Mark to lie still and rub her sopping pussy all over his bare chest while she built up to orgasm. She loved to see her juice glistening on his hard nipples as her stared into her eyes.

But Mark was not willing to lose again. He had given her a head start, but he could tell from her strong scent that she was already worked up. It had been weeks since they had had a chance to be alone, and releasing their sexual tensions with other people was never quite as good. So Mark felt he had an advantage.

Without hesitation, he plunged his middle finger deep into her pussy. Just as he thought, she was soaking, and the finger oozed right in. Melissa cried out and arched her back- she was unprepared for the direct assault on her senses. Mark usually teased her all over her legs- her biggest erogenous zone- before heading into her wetness. He must have really wanted to win.

She caught her breath and grunted, "Ok then!"

She reached down his shorts and began to move her hand right on his hard cock. He gasped again- the feeling of her soft skin on his prick always got him to cum. She was not holding back either.

The two did not exchange any more words. They focused on each other's heavy breathing. The only sound besides that one was that of the rapidly slapping flesh on flesh.

His middle finger forcefully probed her wet hole, rubbing her walls endlessly as his knuckles pressed against her lips when he pushed deep inside her. The rapid in-and-out motion was made more erotic by the wet sounds her juices made as they slurped against his finger trying to ooze their way out.

Her hand wrapped itself around his cock. Using only her thumb and forefinger, she pulled rapidly- almost violently- on his impossibly stiff dick. His precum continually oozed out as she silently willed him to cum before she did. Finally, the heel of his palm hit her clit one too many times, and her hand stopped. She arched her back wildly as her orgasm began to overtake her. Mark did not stop his incessant pounding of her soft sex. Her breath came in gasps as her body shook out of her control, racked by waves of pure pleasure. She squeezed his leg tightly with hers as she reached out toward nothing with her free hand.

Mark silently watched in amazement. He never tired of seeing his twin sister come. It was as if she sucked the whole world right into her pussy and squeezed it with all her might, just trying to get that feeling to last for one second longer.

Soon, she began to come down of that high cliff of hers, and her hips rocked slowly in the afterglow of her pleasure. Mark slowed his finger motion to match her hips, but he didn't stop. He thankfully sighed to himself. He had thought he was going to lose- he was about five seconds away from orgasm himself. Melissa had taken him to the limit- and this trick wouldn't work on her again. He would have to come up with something different next time. Her asshole was rosy red and puckered tight. He figured he'd surprise her there next time. He knew she practiced his techniques on herself so she could get used to the way they felt. She was that competitive. Sometimes she let him watch her 'practice', and coach her to make sure she was doing it right. Getting her to come (and come hard) was a skill that took practice. She loved that he could do it so well to her. Of course, she hated to lose as well.

"Damn it," she sighed, giggling. "At least losing feels soooo good here!"

"Yep," he laughed. "I am the champion!"

"Oh, shut up," she smiled.

"Are you ready, loser?" he asked.

"Oh yeah!" she said, as her eyes flashed. "Give it to me!"

Without a word, she hiked up her nightgown to her neck, exposing her entire body nude for him. He could shoot wherever he liked; those were the rules. She liked for him to blast his cum right on her face. The warmth made her feel safe.

He knew she wanted it on her face, but with only two days left (two days!), there wasn't a chance. He wanted to save the special times.

He kept their legs intertwined, and rolled over on top of her. For just a second, his hard cock rested on her belly while his balls touched her soaked crack. Then he knelt up.

She knew then it was going to be on her belly, which she secretly loved. She wrapped her right leg around his left one, and spread her arms wide.

"Fire away," she said.

It took him all of thirty seconds to come. He groaned loudly as his cock began to jump. She stared at it, fixated. Then his cum exploded out onto her belly. She giggled. He kept stroking as jet after jet splattered onto her creamy skin. Five spurts, then six. She laughed, amazed.

He was finally finished after eight. He had left a massive pool of cum on her taut stomach. Cum swirled in her belly button and flowed all over her. She loved it. She reached down and began playing with it.

"That's quite a load," she said, spreading it all over her body. She rubbed it hard into her nipples, and rubbed it beneath her neck like perfume. She coated her ribs and her arms with the slick spunk.

"Were you saving it for someone?" she teased.

"Two days, you know," he whispered, recovering.

"In two days, that puddle is going to be INSIDE me, brother!" she laughed. "You better start saving up again."

"I will," he said.

And with that, they headed to bed, satisfied by each other once again, and even more excited by the idea that in less than two days, they'd be eighteen.

*****

June 15th was actually a pretty boring day. Melissa had swim practice, and Mark had homework. The first time they saw each other outside of school was at 9 that night. Melissa's fine brown hair was pulled back in a ponytail. Her shoulders were slumped in obvious fatigue. But she perked up when she saw Mark come out of the bathroom.

"Everything come out ok?" she teased.

"Want to inspect it?" he shot back.

She ignored him.

"You're saving up, right?" she asked, concerned.

"My boys are building up like crazy, getting your special present ready," he promised.

She laughed.

"Special present, huh? I can't wait for that."

"Me either," he said. "Can I ask you something?"

"Sure, what's up?" she said.

"Don't swimmers usually shave? You have quite a sexy mound of pubes there, I noticed last night. Last time I saw you, you were bare as a baby," he said.

"Yeah, well, I have a special present for you too," she laughed.

"You mean besides a wet hole that goes inside you?" he asked. "What else could I want?"

"Well, you'll just have to wait and find out," she teased. "Now get out of my way. I have to pee."

"Can I wipe you?" he asked innocently.

She laughed and gave him a shove. *****

The 16th came, and the twins were bouncing off the walls. They had a fun party that lasted most of the afternoon.

"I don't know why you two are so excited," their mother said. "You're not eighteen yet! Not until 3:30 this morning!"

The twins laughed their intimate laugh and said at the same time, "We know."

Bedtime was at ten that night- the twins had school the next day. Of course, they were just hoping to lull their parents to bed.

Mark's alarm went off at 2:30 that morning. Not that he needed any more excitement, but he wanted to make sure he was wide awake. Melissa was not in her room. He put on his sweat shorts and headed out to the roof.

Melissa sighed. There was Mark, right on cue. She wondered if other twins had the same intuition that she and her brother shared. She laughed at him.

"I'm not fucking you in those shorts," she said.

"It'd be hard to get inside you with them on anyway," he said.

"You said 'hard' and 'inside'," she said.

"You know," he said. "We still have an hour left."

She got up from her towel. Her nightgown flowed over her taut and extremely horny body as she walked over to him. She stopped and put her arms around his neck. She whispered, "A technicality."

She leaned forward and kissed him. It was a kiss they had been waiting for for seven years. Gently, her lips probed his, getting used to the taste and texture. His hands fell around her waist as he reacted to her rich kiss. He mentally compared it to all of the others he had experienced, and it was not in the same league. And even though he had kissed her before, those were brother-sister pecks, and they felt completely different. Her lips were soft and wet and controlling. He felt calm as she held him tight- it was good and right.

But her lips were so hot and wet. They felt like her pussy had so many times on his fingers and tongue. Her body was a fire, and it was his job to stoke the coals. For the first time in his life, he felt nervous that he couldn't be what his sister needed.

He broke the kiss. "I—," he started to say.

"I know," she answered. She did her best to relieve his nervousness. She hoped it worked, and when she felt his arms steady around her hips, she knew it had.

He smiled at her. "I'm not fucking you on the roof," he said.

She replied, "You know, we have an hour left."

He stared at her bare ass as she crept back through the window. Involuntarily, his cock jumped in his shorts. "A technicality," he laughed.

The twins stopped inside the playroom to decide where they should head. After a little debate, it was decided that they'd head to Melissa's room, since it was "naughtier" to deflower your sister in her own room.

Locking the door, the twins faced each other. Melissa teased Mark some more.

"You know this is rape if I don't consent, right?" she asked.

"Do you consent?" he laughed back.

"Oh, absolutely!" she said, turning around. "Now strip me, baby!"

He reached for her hips and grabbed the wisps of her nightgown. In a fluid motion, he slid it up her body, making sure the silken fabric brushed her skin. It moved across her stomach, then her ribs, then her breasts, teasing her nipples mercilessly, and then up her arms as she reached for the sky, until finally she was free.

Mark had chosen to stand behind his twin sister as he removed her nightgown. Silently, she reveled in the erotic feeling of it all. The cool air flowed along her legs and up to her soaking (God, was she soaked!) pussy. The motion of Mark lifting the nightgown slowly up her created a draft that flowed upwards, giving her a slight chill as more of her naked body became exposed.

She imagined her brother's increasing arousal as she revealed more and more of herself to him. Of course, they had been naked together many times before… but this time was different. This time they were going all the way. She could just see his face as his eyes traveled up her bare legs, to her bare ass (which she clenched just for him, giggling), and then up her bare back, and up her bare arms, until she was naked in front of him. She could practically feel the heat of his body radiating that close to her. She knew that when she turned around, there would be meaty bulge in his shorts. Her knees quivered just knowing that it was her who caused those feelings. She started to turn around, but her brother's hand on her shoulder broke her out of her erotic reverie.

"Wait," he said. She felt his hand deep on her inner thigh. It pressed there for a second, and lifted away. "You seem to be leaking," said Mark.

It was true that her juices were flowing wildly, but they were obviously so hot that she hadn't even felt them start to run out of her.

"I always want to be stripped like that," she purred as she turned around. "But now it's my turn to do you!"

Melissa knew that Mark did not require the finesse and eroticism that he had used on her. Besides, she was so horny that she probably couldn't have taken the time to be slow and teasing anyway. She looked at his shorts. They were bulging. The tip of his quivering cock was peeking out of the top. He was already at full arousal. They were apparently ready to go. She slipped her thumbs inside his shorts next to his hips, and with one swift motion, she yanked his shorts to his ankles. She giggled as his cock flopped forward in front of her.

"Yow!" he exclaimed.

"Oh, I'm ready, little brother," she told him. "Come get big sister's pussy." "You are two seconds older than me! And in two seconds, you're going to be calling ME big brother!" he told her.

She spread her arms out and flopped backwards on the bed like an angel. He was about to follow when he noticed his present. His sister had shaven her pubic hair into the shape of a heart for him.

"I thought you'd like that," she laughed.

"I make like it, but I love you, Melissa," he said.

"I love you too," she whispered. "But it's finally time. Make love to me."

He crawled up onto the bed. All the nervousness was gone now, thanks to his sister. She had convinced him that she wanted this as much as he did. He leaned forward and eased himself on top of her.

They locked eyes, and for a moment- just a moment- she blushed. Then she gasped as she felt a new sensation. The head of his shaft was pressing against her soaked pussy lips. Even with just a little pressure, they willingly splayed themselves as far apart as they could, begging for more. Of course his cock was much thicker than his finger, but it was also hot… and spongy. The shaft itself was hard, but if she rocked her hips a little, she could feel the head smoosh against her own soft flesh.

This must be paradise, she thought to herself.

She then felt his hands gripping on her shoulders as he set himself up for more leverage. Finally, after so many years of waiting, she was going to make love.

Melissa let out a sigh at the feeling of being penetrated by a penis for the first time. She had expected that she would groan, or maybe scream like she had seen in pornos. But the filling feeling was something she had never expected. She had been fingered by her brother and a few others many times before. She didn't expect the feeling of anything inside her pussy to be different, but this somehow felt… right. It swelled her with a sense of contentment.