Authors Note
I owe some inspiration for this story to another story on literotica called "Wild Wednesday" by Jake Marlow, definitely recommended. The fantasy of suddenly switching bodies or sexes is certainly not original, but many such stories seem to dead end too quickly. Twins also share a significant bond that is worthwhile to explore. This story turned out to be somewhat more complex than I originally intended; it takes place over multiple days with numerous characters, so please be patient getting through the setup.
Any resemblance to real persons, alive or deceased, is purely coincidental.
*****
Prologue
(Sunday afternoon in a Midwest town) "KIDS! We're leaving! See you in two weeks!" Their mother called from the front door. Shannon came in from the living room and gave her a quick hug goodbye.
"Have a good time, Mom," Shannon said tersely.
"Thanks, hon. Love you." Her mom almost teared up during the hug, but was able fake a smile as she stepped back. She knew her little girl had not been happy moving to the Midwest four months ago. Aside from leaving her friends behind, she had to put her burgeoning dance career on hold as she struggled to find a local studio or dance instructor that could handle her level of training and talent.
Shannon had been dancing since she was 3 at a great studio back home, where the head instructor had become a second mother to her. Now 5'6" and 110 lbs, her figure was a stunning combination of slimness, toned muscle and perfect C-cup breasts, with proportionally long legs for her height. She moved with effortless grace when she wished to, and could both jump incredibly high and perform gymnastic tumbling at a high skill level.
She had drifted from one studio to another during the past four months, training as best she could and essentially being her own coach. She had even almost been desperate enough to try out for cheerleading just to have a regular workout after school, but for reasons her Mom didn't understand, she had been ostracized from the team before the tryout took place.
Shannon was dressed as usual in loose yoga pants that hid her fabulous dancer's legs from view. She had become somewhat shy and introverted after the move, and again her Mom had not figured out why, but she hoped her girl would come out of her shell again soon.
Shannon's twin brother Sean came in from the front yard after helping their father load the car with the luggage that the parents would need for a week-long conference and second week-long resort vacation their father had won from work. The twins were finally considered old and responsible enough to take care of the house during the trip.
Sean picked his mother up casually and nearly crushed her in a hug. At 5'11" and 175 lbs, he was a serious martial artist without an ounce of fat who trained for several hours every day. His Mom gave a mock groan as he switched her from a hug to picking her up by the waist, his forearm tendons and veins standing out through his skin. She said, "Put me down, boy, before you kill your poor old mum."
He smiled at her and said, "Take care, but don't feel like you need to call us unless there is a problem. We want you two to relax and not worry about the home front."
Sean's black hair and blue eyes came straight from his handsome father, and contrasted sharply with Shannon's lightly freckled white skin, deep ruby red hair and green-gold eyes that had passed down from her maternal grandmother.
Shannon and Sean had been inseparable as kids, but as puberty began after 12 they had grown apart. Currently, Sean was happy with the move, having found a mixed martial arts gym with great instructors nearby that he could walk to from school or home. Shannon had protested the move vehemently, but was overruled in favor of her dad's career. She and Sean had fought over the move almost as much as she had with her parents, and she had not yet forgiven him for failing to take her side. Even before this, however, the twins had developed separate friends and separate interests. Long training hours kept them from interacting much during the past 2 years as they moved through the latter stages of puberty, growing taller and larger in their respective ways.
The new high school was a mixed bag for them. Neither had been able to overcome the new kid popularity hit, and their outside interests were not commonly shared at the school. No one aside from her new best friend Misty even knew Shannon was an aspiring professional dancer. Sean had made a few casual friends at school and at the gym, but so far no one besides his training partner Oliver had become a close friend.
Sean's good looks had made him successful at getting some dates with the cheerleader crowd despite not playing on the teams, and he had been dating a cheerleader named Erica for about 4 weeks.
Shannon, on the other hand, did her best to conceal her body in oversized jeans and shirts. She had been somewhat popular at her last school, but was passive-aggressively punishing her mother by trying hard not to fit in. She wore her thick-framed glasses instead of her contacts. She even stuffed her gorgeous mass of curly red hair in a hat during most school days and pinned it up in a tight bun on other days and during gym classes, where she also insisted on wearing loose sweats or yoga pants instead of shorts.
Aside from her straight A's, there were two other major contributors to Shannon's social anonymity at the school. The main one was that somehow, without knowing why, she had made an enemy of the most popular girl in school, a tall, stacked blonde senior named Kristen who was head cheerleader. Kristen's disapproval was the social kiss of death. Kristen could have been Kathy Ireland's larger-breasted twin, and the guys in school bent over backward to try to get her to notice and approve of them.
The second factor was a basketball player named Tony, who had dated Shannon soon after she first arrived and seemed really sweet at first. An attempt at losing their mutual virginity went poorly due to premature ejaculation and lack of enthusiasm on Shannon's side. She had not liked Tony's pressure tactics as they were parking one night, but caught in a vulnerable moment in her life, she was convinced to go along and just get it over with. All to her dismay, it turned out, as the condom slipped off his smallish penis soon after penetration of her mostly dry vagina and he squirted all over the place as she pushed him out.
Fearful of her telling the tale to his buds, Tony had further trashed her reputation and called her a frigid little geek. Her hymen was gone, but she got zero pleasure from the whole experience, a huge (or not-so-huge, so to speak) bummer. So far she had not retaliated with her side of the story, but did try rebound dating another guy named Henry a couple of times before moving on.
A recent, promising development in her otherwise non-existent social life was Adam, the starting running back: 6'2" tall, 200 lbs of muscle, but with boyish charm and a crooked smile. He had dated and fucked Kristen every which way for well over a year before breaking up with her last month. No one knew why. The football captain had surreptitiously asked Shannon out on two dates so far, and been very patient and gentlemanly with her for reasons of his own.
Conversely, Shannon was nearly ready to tear his clothes off on their next date. Her hormones had kicked in with a vengeance after the Tony thing went bad, and masturbating had made her want the real thing even more. It had to get better than that first time!
Sean's new girlfriend Erica was Kristen's best friend on the cheerleading team. She was a natural sex bomb, carefully working her way through the local pool of hot guys and not really caring what anyone else thought of her. A long-haired brunette with naturally tan skin, high cheekbones, C-cup breasts, huge brown eyes, wide lips and long legs, she was a star in nearly as many masturbation fantasies around town as Kristen.
Sean was a virgin when they met, something Erica could easily tell. She had ulterior motives for dating inexperienced guys, but Sean was unaware of them. She had started to take him up the ladder of experience. Oral sex had started after she teased him for a few dates, and they had done the deed a week ago in the back of her parents' car.
Unfortunately, Sean's inexperience made him less than memorable for her, and Erica was not a patient teacher. His earlier fumbling while going down on her had been disappointing and he only lasted a couple minutes during intercourse.
Regrettably for him, Erica loved to discuss her sex life in the cheerleaders' section of the girls' locker room, so the remarks and giggles had started to follow Sean as he walked around school. He was still trying to figure out how to deal with his hot, bitchy cheerleader; so far she held all the power, and had not told him everything about her history or plans.
The previous Friday at school, Kristen had stormed up to Shannon and Misty during lunch. "Hey, skanks. I just heard one of you is dating my boyfriend."
The friends glanced at each other perplexed. "Your boyfriend? You mean Adam?"
"Yes. He and I aren't finished yet."
