Lust from Space!

Sara saw the vine wind itself further around Lucy's waist and drape its blunt tip between her legs. Lucy took her mouth from her sister's breast and the girls' eyes met. Sara wished she could see what was happening, but she knew everything when her sister's eyes went wide. "Oh, god," the girl groaned, clearly dealing with the girth. "It's in me."

"All the way?" Sara asked.

"I don't think so," Lucy said. Sara immediately bent and kissed her sister more passionately than she had kissed any boy. Lucy had just begun to return the kiss, when the vine plunged all the way into her. She screamed into her sister's mouth, and Sara's fingertips traced gentle little circles around the girl's nipples, hoping that it would ease the pain. "It hurts!" Lucy cried.

"I know, Lucky," Sara said, calling her by the name she used on the rare occasions that they got along.

The vine pulled back and gently pushed forward again. "Ah!" Lucy groaned again. Now, rhythmically, but still way more gently than it had ever been with Sara, the vine slowly began to pump in and out of Lucy's tight little pussy. "Ow, ow, ow," the girl groaned for a while until finally Lucy moaned, "Oh, oh, oh." The vine stretched her pussy, and now Sara's little sister knew the feeling of her taut little clit sliding against the length of an intruding vine. "Oh, god. God damn!"

"Good?" Sara said, smiling at her sister, hopefully.

"Great!" the girl said, her face flushed. Sara kissed her again, and this time Lucy kissed back just as passionately. The girls' tongues met and swirled around each other in an erotic dance. Soon, both were moaning as the vine sped up its pumping.

After such a long tease, Lucy couldn't last very long, and pulled her mouth from her sister's as she began to come, screaming incoherently. Her body rocked and shook as ecstasy overcame her. The vine kept pumping into her until she began making guttural, grunting noises, and then slowed.

As the vine's fucking of her little sister wound down and the tendrils began to recede from her body, Sara held her. The girl looked worn out, and once the roots released her arms and legs, Sara looked for a place they could rest that wasn't in the dirt. Just next to the tree trunk was a thatched blanket of the same kind of tendrils that had teased them. Sara helped her sister up, and then the two girls staggered to the improvised blanket.

It was strong, but soft, and although the tiny, fuzzy hairs on the tendrils tickled slightly, the girls found it was perhaps he most comfortable thing they'd ever laid on. Sara lay on her back, Lucy on her side, cuddling up close.

"That was incredible!" Lucy murmured into her sister's neck.

"You said it, Lucky," Sara said, wrapping her arm around her sister and stroking her back.

"Where did all this come from?"

"I wish I knew," Sara said, "but I'm not sure it's from around here. Earth, I mean."

"No kidding," her sister said, bringing an arm to rest limply on Sara's belly. "Did you notice that the tree seems brighter?"

Sara honestly hadn't paid attention, but when she looked, she noticed that the veins of glowing gold in the tree's trunk and branches had gotten brighter since the last time. Again, gears in her head turned and clicked. "I have a theory about that," she said.

"'I have a theory about that,'" her sister said in her best Nutty Professor voice. "You're such a nerd!" Normally, this would have been an insult, but this time Lucy giggled and kissed her on the cheek. "So what's your theory, professor?"

Sara stared up into the branches and vines, thinking. "I think that blue tree in the dome is like a beacon or something," she began. "Like an SOS or something."

"SOS?" Lucy asked, clearly not her father's daughter. "Like 'sexy older sister'?"

"You think I'm sexy?" Sara turned her head toward her sister.

"I do now," Lucy said, kissing Sara deeply. When they parted, she said, with lightning speed, "I mean, I think I maybe always had a crush. I don't know. It's weird. You're my sister, you know? And that feels, I dunno, wrong somehow. But I can't help it."

"Wow," Sara said.

"Right?" Lucy said, eyebrows raised. "I mean, you clearly feel the same way about me, too. That's why you brought me here, right?" Sara hesitated a little too long. "Right?" Lucy asked, a little more hopefully.

"I think so," Sara said. "I mean, last night, when I saw you changing," Sara turned on her side, facing her sister, and traced a finger over the girl's breast. Lucy drew in a breath. "I mean, I've seen you naked a million times, but holy cow, you know? And honestly, you were being kind of a brat, and I thought that I'd teach you a lesson."

"You wanted to punish me by giving me the best fucking orgasm I may ever have?" Lucy looked incredulous.

"Look," Sara said, "I'm not the best when it comes to dealing with people."

Lucy rolled her eyes. "Sara," she said seriously. "You thought it was going to be rough, and you wanted it to hurt."

"I," Sara began, feeling ashamed. "I did." She started drawing away from her sister, but the younger girl grabbed her hand and put it back on her breast. Lucy looked into her eyes.

"I don't care," the girl said. "I was being a brat. Unlike you, I am good with people. I always figured if I could get you to what I want, like I can with everyone else, I'd at least have you close. And," she added, smiling, "it wasn't that rough, after all. At least not with me."

"Yeah, that's odd," Sara said. "That was part of my theory."

"Oh, here we go again!" Lucy said, grinning.

"I think that somehow this place knows what we want," Sara said.

"Ooh!" Lucy said, grasping her sister by the shoulder. "I want a million bucks!"

"Sexually, I mean," Sara said. "You were right. The tree is getting brighter. I think this place is powered by sexual energy, or something."

"I guess that makes sense," Lucy said. "As much sense as anything else here." She looked up at the tree, whose veins glowed noticeably brighter than when they had entered. "But I'm not sure."

"Why not?" Sara asked, noticing that Lucy's fingers had begun running sensually down her back.

"If this place knows what we want," Lucy started, her fingertips moving down to trace to contour of Sara's butt, "how come it had to seduce us? I mean, you felt it, too, right?"

"Yeah," Sara admitted, pinching her sister's nipple lightly and rolling it between her fingers. "I don't know. But do you ever think we'd ever be together like this without a little push?"

Lucy's hand moved up, brushing over Sara's breast. When it reached the older girl's shoulder, Lucy pushed and Sara rolled onto her back. "Like that?" she asked, getting up off her side and straddling her sister's waist.

Sara ran her hands over Lucy's smooth, creamy thighs, and drank in the girl's body with her eyes. "Definitely like that," she said, smiling.

"But," Lucy said, "you like it, right? I mean, you're not doing all of this just because this place tells you to, right?"

"Lucky Lucy," Sara, said, reaching up, grabbing her younger sister by the hair that fell down around her shoulders, and gently pulling her down until they were face to face. "I love it. And I love you."

Lucy gave her a mischievous smile. "Then you're going to love this." With that, Lucy grabbed her big sister's wrists and pinned them above her head. Before Sara understood the exactly what was going on, two roots had snaked out from between the weave of tendrils and bound her wrists. As Lucy pulled away, another root wrapped around Sara's waist. Two more popped through the glowing blanket and bound her knees. "Actually," Lucy added, matter-of-factly, "I think I'm going to enjoy this more. You're all mine."

The younger girl took in the sight of Sara's bound body for a few moments, savoring the sight of her helpless sister. It made her incredibly horny to think of what she might do next. The possibilities seemed endless.

"You really do like having power," Sara said, not struggling against her binds, knowing there was no point. "Don't you?" Sara had hoped that the two of them might explore each other's bodies gently as lovers, but there was no question that that was not going to happen. Lucy gave her a questioning look, stood up, and went to find her daypack. Not understanding what question Lucy had asked herself, Sara continued as Lucy returned with something hidden in her clenched hand. "I'd always wondered what you got out of having everyone wrapped around your fingers."

Kneeling beside Sara, the younger girl put a hand on the inside of her sister's thigh and, with the roots' help, spread the older girl's legs. Lucy cupped her sister's pussy in her hand and felt the heat-and increasing moisture, she noticed-emanating from it. "I never wanted anyone wrapped around my fingers," she said. "Only you." With that, she plunged two fingers deep into her sister's pussy, feeling the warm, slick tightness. God, she thought. This was going to be fun.

Feeling her sister's fingers suddenly inside her, Sara jumped with surprise and pleasure, throwing her head back. "Ah-!" she cried, for a split second before Lucy's hand clapped over her mouth, filling it with something soft. Sara recognized the smell of it: Lucy's panties. A small, strong tendril looped over her mouth to keep it in place.

"Now hush," Lucy said, kissing her on the lower lip. "You're such a screamer." Lucy wiggled her fingers in her sister's pussy, feeling it twitch.

"Mmmmf!" Sara said through the wad of cotton.

"You like that?" Lucy asked, devilishly. With out waiting for a reply, she straddled her sister's thigh, keeping her fingers firmly planted in the older girl's pussy. Lucy stretched herself down over Sara's body until her mouth met a nipple and her itching pussy ground against her sister's smooth, toned thigh. She licked, sucked, and teased Sara's breast, fingering her all the while, and the older sister moaned through her gag. Lucy's breath became ragged as she ground her little clit against Sara's increasingly wet thigh.

By the time Lucy switched to Sara's other breast, both girls were moaning and breathing heavily. Suddenly, Lucy lifted her head from Sara's chest and took her fingers from her sister's drooling pussy, and said, "I need more."

Sara was reeling from the sudden absence of pleasure, but snapped back to the moment when her sister yanked the panties from her mouth and replaced it with her tight little pussy. The girl had a little hair between her legs, but it was more like a fine blonde fuzz. Straddling Sara's face as she was, her pussy open and exposed to the older girl's mouth, it didn't really matter.

Sara didn't need a moment to think about it. If Lucy wanted her big sister to eat her pussy, Sara was happy to oblige. She'd never even thought about going down on a girl before now, but she did what she thought she herself would want. Sara started kissing and nibbling the spread-open lips and licked up and down the length of girl's tight sex. Lucy moaned and rocked back and forth a little. Sara stood her tongue up straight and let her little sister do some of the work. She then flicked the girl's hard little clit, and Lucy went bananas. "Oh, fuck!" the girl cried out. "Do it again!" Sara flicked Lucy's clit again, and the girl cried out in pleasure. Now, Sara's tongue made circles around her sister's clit, and the younger girl grabbed her head and pulled it into her twitching pussy. Sara sucked on the girl's button, and Lucy went rigid. When Sara added her tongue, she felt her sister's pussy convulse. "Aaaaah!" Lucy cried as she came, body bucking and shaking. And then the girl went limp, falling sideways off of Sara's face into a twitching, panting heap.

"So ... good ..." Lucy moaned, flat on her back, staring up into the tree branches.

"Oh, it's about to get better," Sara said, now free of the roots.

"Huh?" Lucy asked, but in her dazed state, she didn't have time to react. Four vines had already come down out of the tree and wrapped around her wrists and ankles, and now they yanked her into the air, shaking her out of her stupor. The vines contracted until taut, pulling her arms and legs wide, and the girl whimpered in discomfort. Sara stood in front of her.

"So," Sara said. "When you're in charge, your big sister doesn't get to come. Is that it?"

"No, I-" Lucy started, but Sara put her index finger over the girl's lips.

"It's OK," Sara said, dragging her fingertip slowly down the middle of her little sister's body, causing the bound girl to take in a ragged breath. "We're both new to this, and you, my sexy little sister..." Sara paused, leaning in, sucking Lucy's lower lip, and pulling back until, when she let go, it snapped back against the younger girl's teeth. "You are the younger. How could you have known?" Sara's finger tracked down Lucy's body until it paused just above the girl's wide open legs.

Lucy had never seen her sister like this before. Sara, even though she was older by four years, had always been a follower, much like their father. If she could sum her older sister up in one word, it would be "meek." Or, at least, it would have been. Now, she wasn't so sure. All the previous pleasure they had experienced together-all the previous confessions of love and attraction-all the newly found comfort she had begun to have around Sara seemed to disappear. The vines held her tight to the point of discomfort, but unlike her sister, she still struggled against them. "I'm sorry," she said, and then blurted out in one rapid torrent of words, "I thought you were just going to teach me how to jerk off right and then we ended up down here and you helped me pop my cherry and you said you loved me and then I just got carried away I was so horny!"

Sara tsk-tsked. "I told you: girls don't 'jerk off,'" she said. "You see? How am I supposed to teach you anything if you can't even remember that?"

"I'll learn!" Lucy pleaded. "I promise! Please ..." The younger girl paused, resigning her self to her sister's ministrations. "Please, teach me."

"Teach you what?" Sara said, inching her finger closer to her sister's exposed pussy. The girl squirmed. Fucked for the first time and then eaten out by her older sister: her little clit must be extra sensitive, Sara thought.

"Teach me to finger myself right," Lucy said.

"Mmm," Sara said, pretending to mull the idea over. "Nah."

"But-" Lucy started, and was immediately cut off when Sara ran her finger over her clit. "Ah!"

"Honestly," Sara said, disapprovingly. "No one can teach you how to get yourself off. Only you can figure out the best way."

"But-" again Lucy's objection ceased when Sara plunged her finger in to her tight little pussy. "Oh!"

"What I'm going to teach you, my little Lucky Lucy," Sara said, slipping a second finger into the girl's slick snatch, "is how I like to be fucked. You were oh, so gentle with me, and I've noticed that's how you like it. So now it's my turn. Brace yourself."

The vines binding Lucy hauled her through the air, ripping Sara's fingers from her little pussy and bound her, back first, against the tree trunk. Two vines, one for each girl, descended from the canopy and sprouted the glowing tendrils that sought out the pleasure spots over each of their bodies. Another vine descended, as thick as the one that had fucked Sara senseless earlier, and began winding its way down Lucy's body. Sara, snapping out of the moment for a second, worried that it might be too big for the girl, but when the vine extended itself for her to hold, her lust took over again.

Holding the thick, blunt end of the vine, Sara leaned in and took her little sister's nipple into her mouth. Lucy gasped and then squealed when Sara bit down lightly with her teeth. Rolling the nipple around with her tongue for a minute, Sara again bit down. "Ah! Aah!" Lucy hollered.

"Time to help me cum," Sara said, spreading her own legs, and the vines released Lucy from the tree, flipped her upside down, and pulled her back against the trunk. The younger girl's head hung between Sara's legs. The tendrils on Lucy's body helped prop her head up, forcing her mouth onto the older girl's hot pussy.

At first, nothing happened, but after a moment, Sara felt nibbling and licking on her smooth pussy lips. "Oh, fuck, baby!" she moaned, her knees nearly buckling. In response, the nibbling increased, and every time Lucy's tongue streaked across her big sister's pussy lips, Sara felt herself get wetter and wetter.

Sara, realizing she was still holding the blunt end of the vine, and had her sister's little pussy pinned right in front of her, took the vine and began rubbing its slippery juices up and down Lucy's slit. The licking and nibbling stopped. "Don't stop, baby!" Sara said, pressing her snatch down on the girl's mouth. As Sara began to rub the vine harder against Lucy's sensitive little clit, the girl continued to slurp at her big sister's pussy. "Lick my clit, Lucky!" Sara moaned, and Lucy found her sister's clit and flicked it with her tongue, just as Sara had done to her. "Ah!" she cried.

Sara couldn't stand seeing her sister's pussy empty any longer, and pressed the blunt end of the vine against Lucy's well-lubricated opening. "Mmmf!" Lucy groaned into her sister's sex, but Sara kept pushing. "MMMF!" the girl's muffled groan grew louder. Finally, the vine popped into the blonde girl's tight little pussy, and Sara could see that it was stretched to the maximum. "Mmmm!" the girl moaned, flicking Sara's clit again.

Encouraged, Sara drove a few more inches of the thick vine into her sister, filling the girl up. Lucy just moaned and began sucking lightly on Sara's clit. Sara knew that between fucking her sister's pussy and having her own eaten out, she wasn't going to last long. Lost in lust, Sara began pumping the thick vine in and out of the girl's tight hole, watching as it rubbed against Lucy's little clit. Faster and faster she pumped, and faster and faster her little sister's tongue played with her clit while sucking on it harder and harder. In seconds, both girls erupted into simultaneous orgasm. Lucy squealed wordlessly into Sara's dripping snatch, and Sara pulled the vine from her sister and lapped at the twitching pussy until it stopped.

Slowly, Sara stepped back from the tree and looked down at her sister's red face. Pussy juice and saliva ran down the girl's chin and cheeks, and had soaked into her hair. The vines slowly turned Lucy right side up and released her, and Sara braced the girl as her legs nearly gave way.

"So," Sara said, beaming at her disheveled sister, "what did we learn?"

Lucy, still a bit disoriented, studied her Sara's face for a moment. The cruel disciplinarian was gone, and her loving sister had returned. It had all been an act! "That my sister likes it kind of rough," she said.

"And what else?"

"That you come really hard?"

"Close," said Sara, hugging Lucy to her. "That you can make me come really hard."

"Well, I just followed what you did," the blonde girl said. "I've never done that before."

"Neither had I," Sara said, smiling a sideways smile.

"It looks like we both learned something," Lucy said.

"Mmm," Sara said, running her hands down her sister's back. "I think I learned more."

"Why?"

"Well, you already knew it, but I just figured it out today."

"What is it?"

"That both of us have an incredibly sexy sister," Sara said cupping her sister's butt in her hands. Lucy leaped up and wrapped her legs around Sara's waist, kissing her deeply. Sara, with Lucy attached, backed her sister against the trunk of the tree, and for what seemed like an eternity, they kissed again and again.

Day 3

As it turned out, Sara and Lucy's passion had burned so fast that when Sara checked her pocket watch, she saw that they had two hours to burn before they needed to be back. They leisurely got dressed, Lucy foregoing her panties, now a damp wad, and wandered the corridors for an hour. As they walked, holding hands, the girls pointed out various plants that seemed curious. Some seemed to have very specific shapes, for very specific purposes, not all of which the sisters could decipher. Others seemed odd, only because they were dimly glowing. The girls knew what might bring them back to their brilliance, but were too spent and sore to try-for now. Using the skills she'd learned from the Wilderness Girls and from her father, Sara had begun making a map of the underground structure, and as they went, she taught Lucy as much as she could. They both knew that before this night, neither of them would have seriously asked the other for anything, but now, spending the time together made them not so secretly happy.