EVERYONE IN THIS STORY IS EIGHTEEN OR OLDER.
This is the continuation of Donnie's Dilemma. Donnie lets his Sister, Lucy in on the compound he mixed with his chemistry set. She studies the website where he found the formula and points out things Donnie wasn't aware of when he ingested some of the compound himself. The side effects warn that the compound increases libido in both men and women. It also increases sperm production, longer erections and more sexual sensitivities to the genitals of both men and women. This story is fictional so enjoy it for its entertainment value.
If you don't like reading about incest then stop now and move on to another story. This is not a forum to protest moral issues.
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Donnie woke up to the sounds of birds happily chirping outside the bedroom window. It was just before dawn, and a tinge of twilight lit up the room. It took Donnie a moment to orient himself and realize he was not in his bedroom. He looked to his left and found his sister, Lucy, sleeping peacefully on her back. The top sheet was pushed down around her waist, and she was naked from the waist up. Donnie watched her delicious breasts move up and down with each breath. The details of the previous few hours with his sexy sister flooded his groggy mind. Surprisingly his erection had gone down.
Donnie was able to find his t-shirt but not his boxer shorts. He made his way to the Jack n' Jill bathroom he shared with his sister. Donnie closed the bathroom door connecting his room with his sister's room and deposited his dirty t-shirt in the hamper. He saw his missing, soiled boxer shorts and his sister's panties in the hamper together. He picked up her panties and held them to his nose, inhaling her feminine aroma. Donnie's erection returned with a vengeance, accompanied by painfully aching balls. And his mind flashed back again, recollecting his naked sister on hands and knees in the middle of her bed. He remembered fucking Lucy doggy style while she spouted raunchy words and asked him to fuck her like a bitch in heat. As he harked back to the events of their incestuous coupling, his cock became even harder.
Donnie climbed into the shower, knowing he had to cum to relieve the pain. He began to masturbate as the warm water cascaded over his exhausted body. Every stroke felt better than the previous stroke. He could feel an orgasm building. He pumped his cock, and his orgasm crept closer with each stroke. He pounded away for about thirty minutes but was not able to push himself over the edge. Donnie panicked for a moment knowing he couldn't walk around the house all day with a raging hard-on tenting his pants, and he certainly couldn't endure the pain in his balls.
It was Saturday morning, and no one else was up yet. Donnie dried himself off with a towel and then hurriedly slipped back in bed with Lucy. He leaned over his sleeping sister and lightly tickled one of her bare nipples with the tip of his tongue. Lucy's breathing quickened, and a soft moan escaped her mouth. She didn't wake up until Donnie sucked her nipple into his mouth and began vigorously flicking it with his tongue. Lucy's eyes popped open. When she realized what her brother was doing, she put her hand behind his head and pulled him deep into her bosom.
"Thanks again for last night, Baby brother," she whispered.
"I need your help again, Sis. I've tried jacking off, but masturbation doesn't seem to get the job done anymore."
Lucy smiled at the urgent tone in her brother's voice the thickness of it, letting her know that his need for relief was starting to overwhelm him. She was eager to repeat the events of last night. Lucy wasted no time as she positioned herself between Donnie's legs. Lucy felt a shiver pass through her body when the head of his penis touched her lips. A spine-tingling chill followed that shiver as she took his cock slowly into her mouth, letting it slide to the back of her throat, catching it there...squeezing it with her throat muscles.
"OH, FUCK!" Donnie moaned.
Lucy looked up at her brother and said, "You love it when I suck your cock deep into my throat, don't you?
"I'd be lying if I said I didn't, but we both know I'm not going to cum until I bury my cock in your warm wet pussy."
Without hesitation, Lucy straddled Donnie and banged down onto his cock fast and furiously, coating his shaft in her vaginal fluids. That was a pleasure that Donnie would never tire of, something that made him lose total control of his body. Lucy bounced up and down on his cock, making sounds Donnie never knew she could make. Donnie thrust upward each time she slammed down on his cock. An electrifying wave of pleasure engulfed both of them.
Their lips met, and Donnie began fucking his sister once more. Lucy's pussy began to spasm right away and sporadically squeezed and released around Donnie's cock as a series of orgasms swept through her body. It had an immediate and powerful impact on her brother. With each thrust, their bodies came together with an audible slap. Donnie had to stuff his tongue deep into his Sister's mouth to muffle her screams of delight before they filled the room.
Within minutes Donnie looked into his Sister's eyes and said, "I'm think gonna cum, Sis!"
"Yes! Oh, fuck me, Donnie. Cum inside me... cum inside me again like you did last night! I love the way my pussy feels when you load it with your hot cum."
With a visceral cry, Donnie unloaded everything he had into Lucy. Donnie felt his cock throbbing inside her for an excessive amount of time, and another spurt of his sexual juices accompanied every contraction of her pussy.
"Oh, god! I can feel it squiring inside me, Donnie," Lucy cooed. "It's so fucking hot... don't stop." Lucy wrapped her legs around her brother's ass and pulled him in deeper.
The two siblings stared at each other for a long moment. They were both drenched in sweat and out of breath. Lucy's hair was damp from her sweat and was sticking to her face, but it did nothing to diminish her beauty.
"As much as I would love fucking you like this all day, we need to stop before our parents wake up and catch us," Donnie moaned.
Lucy knew he was right and reluctantly rolled off. Donnie's cock was still hard and throbbing, but the pain had gone away. Lucy asked him why he kept getting hard so often. He told her he would tell her everything after their Dad left for his Saturday golf outing, and their Mom went shopping.
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After their parents left, Donnie took Lucy to his bedroom and showed her the white power; he had made with his chemistry set. He explained the events leading up to his coming to her room and begging for her help. Lucy asked him to show her the website with the chemical formula so she could read about the side effects and warnings.
Lucy studied the information and then asked, "Did you even read the part about side effects and warnings?"
"Not really. I was more interested in getting the formula right," Donnie answered.