Chemistry Girl Ch. 01

"You were going to tell me about your day. Have any fun at school today?"

Lisa then told Mark about her three-week chemistry project with Mr. Thompkins so that her grade in the class could be boosted up to a C-minus. Mark nodded his head while leaning forward to pick up another slice. He then leaned back on the couch and put his arm around Lisa's shoulders, something that was normal for the both of them.

"Oh right!" Lisa exclaimed before placing the remote control on the table and the slice of pizza in her right hand on the edge of the closed pizza box. She then showed Mark the bandage covering the cut on her palm, saying, "I accidentally broke a test tube containing some blue liquid."

"Damn," Mark said as he put down his pizza and then took off the arm resting on Lisa's shoulder. He gently grabbed a hold of Lisa's injured hand with both of his own. Just as his fingers touched her hand, Lisa felt an immediate feeling of electricity travelling between his hand and hers. It wasn't painful, more like a gentle tingling sensation that just as quickly disappeared. She looked up from the gentle caresses Mark was making with his right hand while his left gently held her injured hand. Lisa wanted to close her eyes and just feel Mark trace the tip of his fingers on his right hand around the edges of her palm. Her heart started to race as she heard Mark whisper, "It must have been a bad cut." Lisa opened her eyes and turned her focus to the look of longing on Mark's face as he stared at her hand.

"Mark?" Lisa said just before Mark turned to smile at her while still gently holding her hand, "You seemed out of it just now."

"No, I'm fine," he replied, his eyes locked with her for a few seconds before looking at her hand again. The longer Mark held her hand, the more his expression seemed to slightly change. And the longer he held her hand, the more it felt as if she was feeling something—something she could only describe as a sense of floating above her body. Mark then whispered, "I always used to kiss your boo-boo's away," before he leaned forward and kissed the bandage.

Lisa could not help but smile when he kissed the bandage. Mark and her parents would always kiss her injuries to "make the pain go away." It did not always work, but that act would always get a smile out of her.

Then Lisa's smile stilled when Mark kissed her wrist. She felt his warm lips press onto her skin, and then she felt his tongue gently lick the skin. That act sent more feelings of light electrical shocks travelling through her body. Lisa closed her eyes at the odd sensation—no, not an odd sensation. It was something that was better than odd, as he slowly kissed the length of her lower arm. Lisa leaned back on the couch, her eyes staring at the top of Mark's head as he began gently kissing the inside of her elbow.

"Mark, what are you doing?" Lisa whispered, her voice barely audible, as Mark's left hand now rested on her knee.

Mark stopped kissing the inside of her elbow and looked up. Lisa could see a look of intense longing etched on his face. The look was similar to the look of the man and woman, as well as the driver, on the bus earlier that day. 'No,' Lisa thought, 'the look Mark has on now is more than just longing.' Mark replied, "Kissing your pain away, Lisa." He then went back to kissing the inside of her elbow while his left hand slowly and gently caressed her thigh.

"I want to make you feel better," he whispered again before his lips grazed the exposed part of her upper arm and reached the edge of her sleeve. Lisa looked down at the hand resting on the top of her left thigh. His hand was gently squeezing it now, sending an intense tingling sensation that was starting to travel throughout her body. "Tell me you want me to make you feel better." Lisa looked down at her brother, looking back at her. She had her lips parted and her heart racing in her chest. She did not understand what was happening. This was not supposed to be happening. Not with her brother.

Her eyes followed Mark as he got down on both knees onto the carpeted floor. He pushed the coffee table away with one hand while their eyes were locked. Lisa could see a desire on his face. Such an intense desire had her feeling a wave of different emotions and sensations going through her body.

"Mark," Lisa said, finding her voice as Mark moved his body in front of her until both his hands were on her knees. She felt his hands tighten on her knees. In her mind, Lisa could already imagine her legs being parted. She could already imagine Mark starting to kiss her knees, each one at a time, before slowly grazing his lips on her inner thighs. She imagined this scenario with Mr. Thompkins. But now, here was her brother gently spreading her legs. Lisa was willing herself to say something—to say anything. She saw Mark's eyes shift from her eyes to the valley between her legs. Lisa began to smell a faint whiff of strawberries in the air as the look of desire on Mark's face intensified.

Earlier, she was imagining her brother kissing her thighs, and now it was about to happen.

Lisa parted her lips, but instead of words, a groan came from her open mouth as Mark's hands on either of her legs gently moved up her thighs. Lisa closed her eyes as the scent of strawberries intensified further. It was coming from all around her. She leaned back and rested her head on the back of the couch as she began experiencing the same sensations as when she was about to cum after masturbating.

'And he hasn't even done anything,' Lisa thought to herself. She wanted to stop this before they did something they regretted. 'Fuck!!!' Lisa thought as she felt gentle kisses over the thin material of her pants. She was fidgeting as Mark continued to gently kiss the inside of her thighs while continuing to push her legs apart. As a cheerleader, Lisa could do splits without a problem, so she was aware of how far Mark could push apart her legs. She could tell Mark to stop; it would be so easy.

'Right? It would be so easy, but...' Lisa thought to herself as Mark approached the middle spot between her legs, which she could feel was already starting to dampen. 'Shit, I'm wet! I'm wet!!'

Lisa was breathing hard. Her chest rose and fell rapidly as the scent of strawberries in the air continued to intensify. It was not overpowering enough to make her cough and want to get out of the house, though. Her eyes remained closed as waves of pleasure crashed through every inch of her body.

"Lisa," Mark whispered. Lisa opened her eyes, sweat already forming on her forehead and the rest of her face, before she looked down at her brother staring up at her, his lips about to press into the thin layer of material covering her now wet pussy. She was panting, her lips parted. She licked her lips to moisten them just before she heard a RIP, and she suddenly shut her eyes closed again and pulled her head back. She released a gasp as pleasure shot through her entire body all at once when, without saying another word, Mark brought his lips down onto her bare, wet, pussy lips. He had used his hands to tear the damp part of the thin material covering Lisa's pussy. Lisa couldn't believe what was happening as she writhed and muffled her screams with her own hands covering her mouth. Mark was licking the lips of her pussy before moving his tongue to her clit. Lisa grabbed a nearby couch pillow and covered her mouth with it as a scream of pleasure escaped through her lips. She writhed even more, her body violently shaking in pleasure as Mark sucked her clit while using his tongue at the same time to gently lick it.

Lisa felt sweat all over her body just as she stopped writhing and her body tensed. Her mouth opened in a silent scream, her hands on either side of her—one gripping the couch cushion and the other gripping the couch pillow tight—when Mark inserted his tongue between her pussy lips while using his other hand to gently rub her clitoral area. He was using the pussy juices oozing out of her to lubricate his thump before rubbing her clit. Lisa immediately covered her mouth with the pillow once again as she released a scream of pleasure. Her body felt as if pure pleasure was crashing into every nook and cranny.

"Don't stop!!! Lick it, Mark, lick my cunt!" Lisa yelled out, her voice muffled by the pastel-coloured couch pillow. "Don't ever fucking stop eating me!" Lisa continued yelling out, her voice muffled but still clear for Mark to hear. She continued yelling, "Fuck!"Fuck!! Fuck!!! Fuck!" until her voice was sore. Once her voice was sore, she moaned loudly while grabbing her brother's head as he continued licking her. It was as if he were a savage wild animal eating something he enjoyed. Lisa continued to writhe her body, and her hips continued to be held down by Mark's well-toned arms. She couldn't stop her brother; no, she didn't want to stop him. His lips and tongue felt so good.

Some time had passed, and Lisa was exhausted. She lay back on the couch, her shirt clung to her body; the wet shirt was contoured to the curves of her breasts with her nipples standing at attention, her hair wet with her sweat and pressed down onto her scalp. Lisa still felt waves of pleasure through her body from Mark eating her cunt; he continued making slurping noises as his tongue licked the valley between her legs. Lisa was too tired to scream or moan. She was too tired for her body to even writhe in pleasure. All she could do was slightly moan as Mark continued to lick her slit and intermittently thrust his tongue into her pussy. Lisa did not even know how much time had passed by. She moved her head, hard pants of breath leaving her lips, and widened her eyes at the clock on the shelf.

'Two hours?'

"Mark," Lisa whispered while placing a trembling hand on Mark's head, her legs now just a shoulder-width apart with Mark's head in the middle. "Mark, Mark... stop. I... fuck... that feels so good." Lisa moaned out once again before she gulped and said, "Mark, I'm spent. Stop. You must be exhausted too, so stop." And just as she asked for Mark to stop, he licked her one last time before kissing her clit and then looked up with a gentle smile on his face. Lisa could still smell the scent of strawberry in the air, except now it was co-mingling with the scent of her brother's sweat. Under the glow from the lights at the top of the stairs, Lisa could see her brother was covered in sweat; his mouth and nose were especially slick. His hair was matted down, and his shirt was stuck to his body.

"Did you like that?" Mark said this while struggling to get up on his feet. As he slowly began standing up, he groaned, joking that he must have been on his knees for thirty minutes.

Lisa nodded her head, biting her lower lip, before saying, "It was wow... I don't know why this happened, but... WOW!!" Lisa then coughed because of her dry throat before taking a deep breath and saying, "Mark, it's been two hours."

Lisa stared at the shocked look on his face as he painfully stood up straight. Her eyes went to the bulge straining against Mark's jeans; she couldn't help but wonder what his cock looked like without the jeans. Lisa watched as he turned his head towards the clock and whispered, "What the hell?" He then turned to look at Lisa with a look of disbelief before he limped, whispering "ouch" with every step, towards the empty spot next to the sweat-drenched Lisa. He then sat down, his face wincing in pain, before releasing a breath of relief as he leaned back. She watched his eyes staring at her sweat-covered breast before his eyes looked up. "When did that happen?"

Lisa licked her lips before saying, "When you were licking my pussy like an animal, hell, you were like a thirsty man who just discovered water."

Mark chuckled, as did Lisa, for a few seconds. And then there was silence between them.

"What just happened?" Lisa whispered, breaking the silence. The siblings were now staring at the Netflix menu, which had been on the whole time. She turned her head towards her brother, who was looking back at her. "That went from 0 to 160 in a second." She then quickly added, "I mean, not that I'm complaining or anything. That was my first time someone ate my pussy."

"Your brother ate your pussy," Mark clarified.

"Yes, you are the first one to eat my pussy," Lisa whispered, "but how did it get from here..." Lisa pointed at the injury on her hand and then to her wet pussy, "To here."

"I just knew I had to do it." Mark furrowed his eyebrows before she watched his eyes shift towards her tits once again. "It's like there was this huge desire... this... this lust... I knew I needed to... well..." Mark placed his right hand on her cunt, "to taste this and not stop. All that I thought of was to make you... well..."

"Scream, cum, make me exhausted." Lisa added as she stared at her brother with a smirk on her face. She watched him peel off his wet shirt before throwing it to one side.

"Why didn't you stop me?" Mark asked as he leaned his body towards Lisa, his tongue brushing gingerly against her left nipple, while he slipped his hand down to her slick mound and used his fingers to gently massage her pussy lips.

Lisa's head was still on its side, resting on the couch's back, with her eyes closed as she revelled in Mark licking her nipple and around her areola. She placed her right hand on top of his head as she moaned when Mark took her nipple into his mouth before alternately licking and gently sucking her stiff nipple. While Mark played with her nipple and her pussy lips, Lisa answered his previous question in panting gasps, "I thought about it. But the more you... I mean... the more you... I mean, the more you did the stuff... the more I had this feeling of... I can't explain it. It was like what you were doing made me want you more. Like I needed it."

There was silence in the room for a few minutes; their breaths were the only sound.

"I still smell this scent of strawberry," Lisa whispered as she spread her legs slightly for Mark to insert a finger into her pussy. She closed her eyes and breathed out slowly as her body rang with pleasure once again before asking, "Do you?"

Mark hummed as he licked her nipple before releasing it and saying, "I only smelled strawberries when you walked out of the shower; nothing since then... and definitely not now."

Lisa gasped when Mark leaned back down and took her nipple into his mouth. Lisa moaned "Yeeeeeessssss" as he used his tongue to press down on the nipple while inserting another finger into her slit. Lisa tensed for a few seconds before she relaxed; all the while, she had her head resting sideways on the back of the couch. Her face towards the top of her brother's head as he began sucking her nipple while curling his fingers inside her pussy and pressing up towards her G-Spot.

"Fuuuuuuuuuuuck," Lisa's voice drawled out while she closed her eyes, her lips parting and her heart racing again. She felt Mark release her nipple once again. Lisa opened her eyes to find herself staring into Mark's eyes, the tips of their noses nearly touching each other. She whispered out, "Any regrets?"

"No. You?"

"Noooooooo," Lisa drawled out as the two fingers in her pussy made 'come hither' motions, the finger tips repeatedly brushing against her G-Spot. She closed her eyes again and moaned louder, her legs twitching slightly as Mark moved his fingers faster but at a steady pace. Within a few minutes, there were only the sounds of her moans increasing in intensity and the squelching sounds of Mark's fingers moving rapidly in Lisa's cunt. Suddenly, Lisa gurgled out a yell as liquid sprayed out of her pussy and down Mark's hand, with a lot of the liquid landing on the sweat-drenched couch cushion.

Removing his fingers out of her pussy with a "shlop" sound, Mark kissed the sweat-drenched forehead of his sister and then the nipple he had been focused on before kissing the tip of her nose.

"I still want you, Lisa," Mark whispered as Lisa opened her eyes, a smile forming on her face partly thanks to her latest orgasmic high. "We're going to finish dinner, and then we're going to mom and dad's room."

"Yeeeeeessss," Lisa whispered as she stared at the bulge straining against his jeans. She imagined taking her brother's cock into her mouth while whispering, "Yeeeeessssss."

TBC