EVERYONE IN THIS STORY IS EIGHTEEN YEARS OR OLDER.
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Donnie is the typical annoying teenaged little brother. There is just two years difference in the ages of him and his big sister, Lucy. The immature way he acted, one would think there was much more of an age gap. She tolerated Donnie's juvenile behavior because she loved him. She learned to put up with his pranks because she understood Donnie was going through puberty and was beginning to have an interest in girls. She also knew he was too young and inexperienced to understand why he was attracted to the opposite sex. Every time she had her girlfriends to their home for a sleepover, Donnie acted up.
Lucy is a beautiful young girl with long golden hair, crystal blue eyes, and luscious full lips. She has nice firm tits that are well proportioned for her 5' 4" stature. In other words, she is gorgeous. Donnie is the exact opposite of his sister. He is a tall, gangly boy with freckles and large feet that made him uncoordinated and unsuited for sports or anything that required a degree of agility. Donnie had very few friends. Lucy, on the other hand, was one of the most popular girls in school. Lucy was a boy magnet, and boys would fall all over themselves to be near her. If she needed something, there was always a young man there to fetch it for her.
Lucy was captain of her cheerleader squad, president of her senior class, and was elected homecoming queen two years in a row. Donnie wasn't exactly ugly, but he seemed to repel most girls with his unpredictable conduct and unappealing appearances. He was somewhat of a nerd who enjoyed science and computers.
Donnie had a chemistry set and often found chemical formulas on the internet to use with experiments and pranks. One of his favorites was hydrogen sulfide (rotten egg gas) that he released one night when his sister had a slumber party. Lucy's bedroom smelled like farts the rest of the night, and the girls had to move their slumber party down to the den.
By the time Donnie was eighteen and a senior in high school, he was still a virgin and didn't have a girlfriend. He had started to notice tits more but had only seen naked ones on the internet so far. The only thing Donnie knew about sex, he had learned from watching porn sites. He still didn't know how to relate to the opposite sex successfully. He was somewhat like a ten-year-old boy who chased and pulled the hair of girls he was attracted to on the playground. He knew it was time to grow up and learn to act like a sexually experienced teenager.
Donnie was desperate to get a girlfriend and lose his virginity, so he checked his porn sites to find out what girls wanted in a boyfriend. He noticed that all the men on the porn sites had ten to twelve-inch cocks. Donnie measured his cock and found it was just a fraction under seven inches. Donnie thought he had to find a way to grow a long cock if he was to compete. He searched the internet and found a chemical formula that promised a bigger, harder cock and also claimed it would stay hard until a girlfriend was satisfied. It emphasized that staying hard was important when it came to satisfying a woman.
Donnie got his chemistry set out and worked all afternoon, perfecting the compound that implied powerful anatomical changes to his cock. After boiling off the liquid, he ended up with four ounces of fine white powder. The internet directions guaranteed that one teaspoon of the powder in a cup of liquid would deliver the pledged results. Donnie drank the concoction and set about waiting for the reaction to take place. By dinner time, nothing had changed. His cock wasn't any longer, and he didn't feel any different.
After dinner, the family settled in the den to watch TV together. Donnie was fidgety and kept leaving the room every twenty to thirty minutes to check and see if there were any changes to his cock. There wasn't. He did seem to get an erection at the slightest stimulation, but that was fairly typical for a teenage boy with raging hormones. Around ten o'clock, the family retired to their bedrooms for the night. Donnie had a restless night. He kept dreaming of naked girls parading before him. Every once in a while, his dream would include his mother and sister among the naked girls.
Donnie came down for breakfast the next morning and took a step into the kitchen. His Mom was busy preparing breakfast as usual, but something was different. Donnie shook his head and looked again. Why hadn't he noticed the flare of his Mom's hips before? She was wearing a dark knee-length skirt and a sheer white blouse that sort of hugged her waist. Her butt curved nicely under that skirt. The outline of her lacy white bra was unmistakable under her sheer white shirt. Was that sexy? For the first time in his life, he thought it was. He could see the swell of the right side of her boob under her shirt, jiggling as she stirred the pancake mix with a large spoon. "Holy cow," he thought to himself. He had never noticed before, but his Mom was hot. He got an erection looking at his Mom. He had to sit down and hide it from her.
A moment later, Donnie's sister entered the kitchen and took her usual place across the table from him. Looking up from his breakfast, he stared at his big sister. How had he not noticed how pretty and delicate she was? Soft blue eyes. A warm, engaging smile. His older sister looked different. Her bra straps are visible on her narrow shoulders. And her boobs? Oh, God, her boobs are small and firm, just hanging out right there for him to admire. How had he not noticed her tits before? The truth is he'd never noticed Lucy sexually before. Her trim little hips. Her dainty nose. Her long, slender neck. How had he never seen it before? She noticed Donnie staring at her boobs and blushed. He tried to smile at her. His cock got uncomfortably hard, and he attempted to acclimate it covertly. His Mom gave him a quizzical look. Donnie tried to engage his big sister with small talk about the yearbook she was editing for her college but kept stumbling over his words. He finally gave up and excused himself and left for school.
Donnie's cock hadn't made the changes promised on the internet, so he studied the chemical formula and decided that the dosage must depend on body weight. Instead of one teaspoon of the white powder, he put a tablespoon in a cup of hot tea and drank it with his dinner. At about two o'clock in the morning, Donnie woke up. It was still dark outside. He rolled over in his tangle of sheets and groaned. Something felt odd. Very odd. He tossed and turned, trying to get comfortable. Something was wrong with his cock. Donnie rolled over, jumped out of bed, and pulled down his boxer shorts to examined himself. His cock was hard, very hard. It was not any longer, but it was swollen fat and ached terribly. It was the worst case of blue balls he had ever experienced. He urgently needed to cum. Donnie rushed to his bathroom, pushed his boxers down to his ankles, and began to masturbate aggressively. He tightened his hand around his hard cock and pounded away. Images of his Mom and sister surged into his head. He seized his cock and increased the rhythm. He was harder now than he had ever been in his life. His cock was, indeed, a sight to behold. The head was purple and mushroom-shaped. The veins were sticking out and throbbing.
An hour later, Donnie still hadn't cum. Blood drained from his head and filled his swollen cock. He was becoming dizzy, and his arms felt like they were about to fall off. He'd never experienced anything like it. He waddled over to the bathroom window with his boxers still around his ankles and pulled the window open. The cold, crisp air cleared his head. Donnie kicked his boxers off and deposited them in the clothes hamper. Donnie shared a Jack n' Jill bathroom with his big sister, Lucy. He opened the door that connected the two bedrooms and made his way to his sister's bed. Donnie sat on the edge of his sister's bed, crying because of his painfully hard, aching cock. He sobbed in pain as he shook her shoulder. She woke with a start and said, "What is it, Donnie? Why are you crying?"
"It's my cock," he blubbered. " It hurts so bad I can't stand it."
Lucy sat up in her bed and saw that Donnie was nude from the waist down, and his cock was standing at attention. Lucy had never really given much consideration to her little brother's cock other than the few times she noticed his arousal creating a bulge in his pants.
"What the hell do you want me to do, Donnie? I'm your SISTER! I'm not supposed to see your... your... thing ... like that.
"Please help me, Lucy," he pleaded, "I just need to cum."
"Well, go in the bathroom and jack-off, or spank your monkey, or whatever the hell guys do to make themselves cum," Lucy bellowed.
"I've been beating off for over an hour and a half. I've come close, but I haven't been able to push myself over the edge and cum," Donnie explained to his sister. "I thought maybe if you did it, I would finally cum."
"Donnie! I'm your SISTER! I'm not supposed to touch my brother like that. It's not right. It's called incest."
" Please! Please! Please, Lucy! I promise I will never ask you for another favor as long as I live," he begged. "Just help me cum this one time."
Lucy considered the agony on her little brother's face. Her heart went out to him because she could see he was sincerely hurting. Lucy relented and asked her brother to lie on his back. She then crawled between his legs. Lucy set back on her heels and examined Donnie's cock for a moment. She had seen a lot of cocks, but never a cock this large. Lucy dated a lot of guys in high school and college and had become very skilled at giving a handjob. It wasn't one of her favorite things, so she learned to get them off quickly.
