16-year-old Darryl stepped out of the strange store and heard the bell above the door ring as it closed behind him. He strode away quickly, his hands in his jeans pockets, feeling the small glass bottle that he had shoplifted.

He had found it on a shelf in the weird knick-knack shop with a small piece of worn paper attached with twine that said in a spidery script, "Mix one drop with one drop of your essence. Whoever consumes that will desire y..." The writing had become illegible at that point...the paper was very old, and looked to have been chewed on by something. Still, what he could read was enough; a love potion! He couldn't afford the $250 price tag, so he had palmed it and skedaddled. Most likely it wouldn't work, but with his five-finger discount, he wouldn't have lost anything by trying.

Finding the bottle had been good timing, as his sister's gorgeous friend Keira was sleeping over that weekend. He'd had a crush on her since forever, but the 17-year-old blonde barely acknowledged him. Well, with this stuff, maybe she'd do a lot more than that!

Back in his room, he considered the instructions. "Essence"? Just thinking about Keira's naked hourglass figure riding his cock made it rise to the occasion. Within a few minutes he was spewing his teenage cum into a tissue, which he then tossed into his trash bin.

After zipping back up, he had an idea. Essence! Duh! He rushed to the kitchen, mixed up a glass of lemonade, and then brought it and the spoon back to his room. He used the spoon to scrape what he figured was a drop of his cum out of the tissue, and then very carefully unstoppered the bottle. He couldn't tell what was inside by sniffing, so he gingerly tipped the bottle over the spoon's bowl. It came out slowly, like syrup, but it was clear. It was easy to obtain just a single drop, which he then mixed with the drop of his semen using a pencil tip. Once the two solutions became a mixture, he used the spoon to stir the lemonade some more. When he took the spoon out it was clean, and the lemonade didn't look any different.

Smiling, he went to his sister's room and knocked. "Yeah?" That was his sister Meredith's voice. Darryl opened the door and went in to find the two girls already in their bed clothes, which consisted of a cropped t-shirt and panties which showed off their midriffs and long legs. The girls were playing Mario Kart on his sister's Nintendo Switch, and couldn't take their eyes off of the screen for fear of losing the race.

Meredith gave him the briefest of glances. "I said 'Yeah?', not 'Come in.' What do you want?"

"I brought a lemonade for Keira," Darryl offered, holding it out to her.

Keira continued looking at the screen. "Oh, thanks, Darryl, just put it there, okay?" She gestured with her head to the shelf behind them. He put it there and waited.

"Nothing for your loving sister, bro?" Meredith asked, concentrating on a particularly tough curve.

He realized that he had goofed by only bringing one drink. "Oh, uh, right! I'll grab you one too." He rushed out of the room.

When Darryl returned with the second, untainted lemonade, he noticed that the first glass was now half finished. He handed the new one to his sister. "Thanks, bro!" she said, and then noticed how lecherously he was looking at her friend Keira. "Now get out."

---

Darryl purposely didn't whack off that night, even though his cock had recovered from the earlier masturbatory session by the thought of Keira stealing into his room to take his hard cock into his mouth while he slept. He could practically feel her hot tongue licking up his shaft before engulfing it entirely, sucking hard and moaning in pleasure...

Wait, he thought as he woke up, this was actually happening! In the gloom of night he could see the shape of Keira's head under his sheets bobbing up and down on his hard-on. It felt incredible!

Oh my God, it fucking worked! he realized, laying his head back and savoring the feeling of his first blowjob.

"Mm...mm!" he could hear her moan under the covers as she sucked harder and moved her mouth faster up and down on his cock. She was really good at this, and he was going to cum soon.

He stiffened his stomach muscles, pushing his pelvis up as he felt it start. "Oh...ohh...gonna...uuaaahhh!!" He felt his dick expand as his cum rushed up the shaft, blasting out into Keira's mouth as she moaned and sucked. Darryl marveled at how much better it felt to cum inside a woman's warm mouth than into a tissue.

She gulped down all of his cum and then fell to the side of his legs, jerking and moaning. Was she...crying?

He lifted up the sheet and reached out to stroke her back. "Hey, it's okay. That felt really good, Ke--"

The face of his dark-haired sister Meredith looked back at him, her eyes full of lust as she finished her own orgasm.

---

Last night:

"Nothing for your loving sister, bro?" Meredith asked, concentrating on a particularly tough curve.

He realized that he had goofed by only bringing one drink. "Oh, uh, right! I'll grab you one too." He rushed out of the room.

While he was gone, the young women finished the race, Meredith having beat Keira by a mere second. "Phew!" Meredith huffed, and grabbed the lemonade her brother had brought in.

She had downed half of it before Keira noticed. "Hey, that was for me!"

Meredith looked at the glass. "Oh, sorry; I was parched. He's bringing another one." She plopped the glass back where her brother had left it.

When Darryl returned with the second, untainted lemonade he noticed that the first glass was now half finished. He handed the new one to his sister. "Thanks, bro!" she said, and then noticed how lecherously he was looking at her friend Keira. "Now get out."

As he closed the door behind him, Meredith passed the new lemonade to Keira, who sipped at it. Meredith then gulped down the rest of the tainted one.

---

"Ke--Meh...Mer?" Darryl stuttered. His sister had just sucked him off!

She stopped shaking. "Hey, bro...hope you don't mind, but I really needed to do that. Can you...go again?" She started to stroke his softening cock.

He sat up, pulling his member from her grasp. "Shit! No...I...no!"

She looked disappointed. "One-timer, huh?" She slipped from under the bed covers and stood up. "Okay, I'll catch you in the morning, then."

As she started to leave, Darryl spoke up, "No! This can't happen again. Mer, did you drink Keira's lemonade?"

She turned back. "Yeah, I did...wait, did you spike her drink? You fuckin' pervert!"

Darryl hissed for her to be quiet. Their parents were away for the weekend, but he didn't want Keira to hear this!

His silence spoke volumes. She moved back to the bed. "You're gonna give me what I want," she said as she patted his crotch, "or I'm gonna tell Mom and Dad what you did. Got it?"

"I...okay..." Darryl whispered. He couldn't believe the situation he was in!

---

Darryl woke up early Saturday morning and was eating cereal when Meredith walked into the kitchen/dining room. She normally got up late on weekends so he thought he was safe. She was still wearing her crop top and panties, the brunette's slim build accentuated by the tight and revealing clothing.

"Hey, bro," she said as she crossed the room, swinging her hips sexily. She stuck a finger into his cereal and then brought a milk-covered digit to her lips. "Mmm..." she moaned as she sucked on it. Looking at his shocked expression for only a moment, she ducked under the dining room table.

"Mer!" Darryl hissed, and then he felt her unzipping his shorts. Despite the bizarre situation, his cock had started to fill with blood, and once she had taken it into her warm hand, he was lost. Soon his cock was inside her hot mouth again. "Oh, God..."

Keira walked into the kitchen a couple of minutes later, her eyes blinking in the early morning light. "Hey, Darryl," she said, "seen your sister?"

Darryl froze. Keira couldn't see Mer under the table due to the interposing kitchen counter, but if the blonde stayed for any length of time she would figure out what was happening under there!

"May--maybe try the basement?" he suggested.

"Oh, okay." As Keira was about to leave she figured she'd give the cute, awkward Darryl a little thrill first. As she was about to leave, she bent over to massage one defined calf muscle, as if she had a small spasm there. "Mmm..." she moaned.

At the sight of the voluptuous young woman's panty-covered ass sticking out as she bent forward, Darryl's cock suddenly filled up to maximum blood capacity. "Uh..."

Then Keira, satisfied, moved out of the room and down the stairs.

"Fuuuccckkk..." Darryl moaned as he came in his sister's mouth. He closed his eyes, imagining that it was Keira sucking his load for all she was worth and moaning in pleasure instead of his sister.

Then it was done and Mer clambered out from under the table. As she did, Darryl noticed a dark patch in the crotch of her panties before she stood back up. Then he tucked his shrinking cock back into his pants.

"Later, bro..." Mer promised as she sashayed out of the room.

---

The girls put on their bikinis and hung out in the backyard catching some rays. Darryl knew they'd be thirsty, and there was more of the potion in that bottle...maybe he could still get Keira hooked on him, and he'd figure out what to do about his sister later.

He whacked off again, which was a little difficult due to his sister draining him earlier, but watching Keira's tanned body through the back windows of the house gave him the inspiration he needed.

"Drinks!" Darryl said as he brought out two glasses, one with Coke and the other with Sprite. He knew his sister hated cola, so he had put the stuff into that.

As he returned to his vantage point at the back window, he heard one of the glasses smash on the patio. "Oops!" His sister said, "I'll get you a fresh one." He saw her head indoors.

"Fuck!" he swore to himself, and rushed down to head her off.

"Siddown!" she said in a commanding voice as he approached her. Uncertain, Darryl did so.

Meredith knelt down, giving him an eyeful of the cleavage between her medium-sized breasts in her bikini. She grabbed his balls through his shorts, making him groan in discomfort.

"This is mine, and I'm not sharing. Stop trying to spike Keira's drink. Got it?"

Darryl nodded. She let go, and then went into the kitchen for a replacement Coke and a broom.

---

Later in the afternoon, Darryl was peeing in the ensuite bathroom that separated his and Meredith's room. He heard the handle click on his sister's side.

"Occupied!" he called out. He always locked both doors when he went in there. Once she had walked in on him pooping; never again!

A moment later he heard a scrape from her door handle, and then the sound of it unlocking. "Mer!" he yelled as her door opened. She slipped into the bathroom and locked the door behind her. She was still in her bikini. Darryl gave his dick a shake as he finished and tucked it away. "What are you doing?" he hissed.

"Coming for what's mine," she said, moving forward and kneeling before him. She unbuckled and unzipped his shorts, dropping them and his underwear to the floor. Then she started to stroke him.

"Mer! I just peed, and I haven't even washed my hands!" He was keeping quiet, not knowing where Keira was.

She continued stroking as his member betrayed him again. "Psh! As if you were going to wash..." Then she took his hardening member into her mouth.

"Fuck..." Darryl moaned. He closed his eyes and thought about Keira again. He didn't find his sister sexy -- well, not really...she was in good shape, sure -- but damn she was good with her mouth!

He found that he didn't know what to do with his hands as he stood there, so he put them on his hips. No, that felt weird. He moved them onto his sister's head and that felt more comfortable. She didn't stop him, so soon his hands were gripping her head a little, urging her to move forward and backward as she sucked his cock.

Yeah, c'mon, Keira, he said in his head, suck that cock, you sexy slut. Soon I'm gonna give you a nice little protein shake... Ohh...Keira...Keira...Keeiiirrraa...

Then he was cumming in his sister's mouth and she was sucking hard and moaning.

*Knock knock knock!* "You gonna be done in there soon?"

It was Keira! Darryl pulled back, dislodging his cock from his sister's mouth and shooting the last few spurts onto her chin, chest, and stomach.

Meredith groaned, looking down at the mess. "Might be a while!" she called out.

"Okay, I'll use the one downstairs."

Darryl tucked his cock back into his shorts. "Sorry," he said as he retreated to his bedroom.

---

That night, Darryl again woke up to his cock being surrounded by warm, wet pleasure. Except this time there was a weight on his hips. Meredith was on top of him!

"Huh...huh...huh..." He could make out his sister's face, and her naked chest below that, her breasts bouncing as she thrust her pelvis into his.

They were fucking! More accurately, his sister was raping him!

He grabbed her hips, trying to lift her off of him. "Mer! Stop!" he urged quietly.

She struggled to get his cock all the way back inside her again. "No! Give it to me!"

She was not being quiet this time. Darryl covered her mouth with one hand, but the other remaining on her hip was no longer sufficient to keep her still, and she sank all the way back down on his hard cock. They both groaned in pleasure.

He let go of her hip but kept his hand on her mouth. "Stop! This isn't right...I'm your brother!" he urged. Then he felt her licking his palm. "Ew!" He drew it back.

She continued riding him. "Too late...we're already doing it, bro. Now give me what I want."

Darryl could feel that he was getting close. His sister was not only older, but she had always been bigger and stronger than him. He couldn't fight her. "Shit...I'm gonna cum soon..."

"Yes...yesss..." She rode him harder.

"Ohh...ohhhh...gonna..." He lay back, trying not to look at his sister.

She was huffing and ramming her hips down onto him for all she was worth.

"Ahuuuhhhh!!" he grunted as he came. As he shot his incestuous sperm inside his sister's hot pussy she thrust her hips down one last time and went rigid.

"Hhhhhee..." she whined as she came hard.

Darryl felt her insides squeeze his cock. "Oh fuuuckk.." he moaned as spurt after spurt of his cum was milked from it. Despite the insanity of the situation, he noted that, as good as blowjobs were, cumming inside a woman was even better.

Finally, she collapsed upon him. Darryl found it difficult to breathe. "Mer...Mer..." he wheezed. He could still feel her insides squeezing his cock, though not as intensely.

She pulled forward and off of him, and they both groaned at the sensation. Then she was on her feet and heading back to her room.

"Mer!" he hissed at her. She turned. "Was it okay for me to cum inside you?"

"Oh, soooo okay..." she replied shakily. Then she left.

Darryl figured he had to trust his sister on that. She wouldn't do anything dangerous because of the potion, right? She was probably on the pill.

---

After breakfast, Meredith said that she had to go to the store for something, and Keira was staying behind. As his sister left, she said she wouldn't be long, and gave her brother the two-fingered "I'm watching you" signal when Keira wasn't looking.

'Fuck that,' Darryl thought, and soon he brought a glass of tomato juice to Keira while she waited in the living room.

"Oh, thank you, Darryl," she said as she took it. "I love tomato juice..."

Soon the glass was gone, and Darryl watched her expectantly from the couch.

She blinked, sniffing the air. "Oh, Darryl, you smell nice..." She got up and joined him on the couch.

"Yeah?" he asked as she got closer and closer, her nostrils opening to fill with his scent.

Keira took Darryl's hand. "Mmm..." she moaned, and started to lick one of his fingers.

---

Earlier that morning:

Darryl thought about the potion. His cock represented sex, so his sperm was the essence of that. Consequently, when his sister had drunk his sex essence mixed with the potion, she then desired to have sex with him, as per the potion's instructions.

He couldn't keep going like this, though, and he really wanted Keira! But did he want Keira to just be a sex slave? No. Maybe? No. He wanted her to love him.

Love! What was the essence of love? The heart represented love, and the essence of the heart was...

He mentally kicked himself. What an idiot he had been!

After breakfast, Meredith said that she had to go to the store for something, and Keira was staying behind. As his sister left, she said she wouldn't be long, and gave her brother the two-fingered "I'm watching you" signal when Keira wasn't looking.

'Fuck that,' Darryl thought. He rushed first to his room for the potion, and then to the kitchen. He grabbed tomato juice, a sharp knife, and a spoon. He cut the tip of his index finger and dripped a drop of blood into the bowl of the spoon, followed by the last drop of the potion. He then mixed it into the tomato juice.

---

The previous day:

Darryl tucked his cock back into his shorts. "Sorry," he said as he retreated to his bedroom.

As he left the bathroom, Meredith, spattered with her brother's cum, used her finger to take gobs of it from her chin and chest and sucked them into her mouth. Mmm! She had a mini-orgasm at the taste.

As she reached for the cum that had landed on her stomach, she found it had dripped down to her bikini bottoms. Her pussy was throbbing. She wondered...if it felt good to swallow Darryl's cum, how would it feel if some got into her pussy?

She gathered the cum on her finger. Her pussy lips were engorged, so it easily slipped between them. Meredith pushed her brother's sperm inside her vagina.

She fell to the floor, cumming hard. "Ohhh fuuuccckkkk..." she moaned as her vaginal walls pulsated around her finger.

When she recovered, she knew she wouldn't be giving any more blowjobs. If it felt that good with just a little of Darryl's cum inside her pussy, how good would it feel for him to blow his entire load deep inside her?

She needed to get all of his cum inside her! She had felt like this since the previous night. Her body starved for it.

---

Keira took Darryl's hand. "Mmm..." she moaned, and started to lick one of his fingers.

"Oh yeah..." Darryl said, moving closer.

The Keira started to suck hard on the end of his finger...the finger he had cut a couple of minutes earlier.

"Ow! Hey..." Darryl tried to pull his finger back but Keira wouldn't let go.

Crunch!

Darryl's finger suddenly experienced all of the pain in the world. She had bit him! "AAAHH! STOP!"

Crunch!

"AAAIIEE!! NOOOO!!"

---

When Meredith returned from the drug store with the Plan B, nobody came to greet her. "Hello?" she called out. She heard sobbing from the living room.

There she found the dead body of her brother, a chunk missing from his throat and one of his hands a ruined mess. There was surprisingly little blood on the floor. Keira sat in the corner, rocking back and forth, staring at his body. Her mouth, chin, and shirt were stained bloody red.

---

The old shopkeeper stoppered up the latest batch of the potion and wrote out the instructions in his spidery script:

Mix one drop with one drop of your essence. Whoever consumes that will desire y...

...et more of that essence, to the exclusion of sense. Suggested substances are spittle, sweat, or sexual fluids. Never blood.

---

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