All characters in sexual situations are 18 or older. Thanks for reading!
"How's my guinea pig this morning?" Violet knocked on Jackson's open bedroom door as she walked in. Her poor brother looked so frail in the cool morning light. Her serum had really done a number on him. Well, the mass and energy needed to create that gigantic dick had to come from somewhere.
"Oink oink." Jackson looked up at his big sister. She was always such a terrific role model. He'd always looked up to her. Recently, he'd also focused on how pretty she was with her playful, hazel eyes and enchanting smile.
"I don't think guinea pigs say oink." Violet flashed that smile. "Seriously, how do you feel?"
"Getting better." Jackson sighed. "But... to be honest, my balls still hurt." He put the book he'd been reading in his lap and tried to sit up in bed. It wasn't easy to turn pages with bandaged hands, but he was making do.
"That's not surprising. The serum has you producing semen at an accelerated rate." She paused as she saw the alarm in Jackson's brown eyes. "Don't worry. I should be able to reverse everything." Violet walked across the bedroom and stood by the bed. Her white lab coat was rumpled and stained. In her left hand she held a beaker. A towel was neatly tucked under her right arm. "Those samples you gave me really helped my work, Jackie."
"That sounds like good news." Jackson nodded, relieved that he wouldn't have to live with a ravenous sex drive forever. "Will my... dick go back to its normal size?"
"I think so." Violet gave him a nervous smile.
"Is there a 'but' coming?" Jackson's eyes fell to the beaker, and he thought he knew what she'd say next. He could feel the blood coursing to his dick as it swelled under the covers.
"Well..." Violet could see the blanket move as her brother's monster hardened. A monster she had accidently created. "To make the counteractive serum, I'll need more samples." She placed the beaker and the towel on his bedside table.
"I still can't fap." Jackson held up his bandaged hands.
Butterflies fluttered in Violet's stomach. "You need my help again?"
"If you want those samples..." Jackson pushed the covers off himself and his dick sprung out. His mom had said it was like two coke cans stacked on top each other. She was right. He moved his legs to the side and sat on the edge of the bed. "... I'll need your hands. Mine don't work." He nodded to the floor between his legs.
"You want me to get down there? On my knees?" Violet couldn't look away from her brother's boner. The cock looked like it was made for one thing. Destroyer of pussies. When all you have is a hammer, everything looks like a nail. What did women look like to Jackson now? "Getting down on my knees is something I'd only do with Chad." The thought of her boyfriend made Violet blush. But she lowered herself to her knees. What would Chad think if he knew what she was about to do?
"It'll be quicker this way, Vi." Jackson's balls pulsed with persistent, aching pain. He needed to empty them.
"I suppose." Violet took the towel from the table and placed it across his thighs to catch the cum her beaker wouldn't hold. She spit into her hands, reached up, and grasped the cock. Her hands looked so small as they pressed into the spongy flesh. "I'm doing this for science, right?" She gave a nervous laugh that quickly died away. Her hands moved up and down along the shaft.
"Aaaahhhhhh. Right." Jackson's dick surged with pleasure. Before the accident, nothing had ever felt so good. "Keep doing that."
"Sure." Violet's thin arms worked hard to bring her little brother off. Her gaze didn't budge from her task and her expression took a far-off look. Her jaw went slack, and her pupils dilated. After a while, she looked up into his face. It was clear Jackson was enjoying himself. "Should I get the beaker? Almost there?"
After his mom's blowjob yesterday, it didn't seem that a handjob was going to do it for him anymore. "Something's wrong. It's not working."
"More spit?" Violet was doing her best to not get turned on by her brother, but it wasn't working. She could feel her wetness between her legs.
"I need you to use your mouth."
"Wow." Violet's hands stopped, but didn't leave the cock. "That's asking too much, Jackie. I mean, you're my brother. And what about Chad? Maybe I can find a friend to come over and finish or something. Sheila's sort of a slut. I bet she'd do it if I begged."
"You need to finish it now." Jackson's voice carried a menace that surprised him and his beloved sister. "I need to cum." His eyes went fierce and his brow furrowed.
"I..." Violet looked up at his face and couldn't believe the intensity she saw there. She kept her hands paused on his penis.
"Your mouth." Jackson gritted his teeth.
Without another word, Violet leaned forward, opened her mouth very wide, and sucked in his cockhead. Her hands resumed their work on his shaft. She made the most obscene noises as her head bobbed. "Uuuuggghhhhhh." Her pussy flooded her panties.
Jackson's face eased and he sighed. "Thank you, Vi." He watched her sweet, pink lips contort around the bulbous head.
