The Warthog's express stood hissing at the platform nine and three-quarters of King Cross station as if straining at the leash, wanting to be set free, to thunder along the steel ribbons delivering its cargo of students to the academy of wizardly and witchcraft.

Most of the students had boarded the train, ready for the Halloween term. Among those still milling around was Warthog's star pupil, Barry Potter and his friend Ron Weasel. Barry was whispering in his ear, Ron's eyes widened as he listened to what Barry had to say.

"You must be joking. Your spell will turn any girl into a nymphomaniac?"

"Any girl at all," replied Barry. "And it can be arranged that she has no memory of being fucked after we are finished with her."

"Wow! Do you intend using it?"

"Of course. We could have some fun on the trip to Warthogs."

"Wow!. Who should we use? That red-head in..."

Barry interrupted him, "I thought Harmony."

Ron's eyes blinked, the grin left his face. "Hang on Barry, Harmony and I have been getting close the last term."

"Have you touched her tits?"

"Well...no."

"That means you haven't had your hand up her skirt and she hasn't given you a wank. You're not that close."

"She's not that kind of girl. She's well brought up."

"With my spell she will be any kind of girl you want her to be. This is your chance, Ron. You can feel her tits, Ron. She could give you a blow job, Ron. You can stick your cock in her, Ron and fuck her, Ron."

"Wow!"

It had taken some time for Barry Potter to find the spell that would open his father's note books of spells and charms. The one detailing sex magic had proved particularly difficult but the effort had been worthwhile. As far as he knew he was the only one who possessed the incantations and wand movements that produced the desired effect.

Barry had tried a spell on his uncle and aunty and their fat slug of a son. He had watched with increasing delight the son fucking his mother on the lounge carpet and then the father sodomising the son, causing him some pain. He had been tempted to leave the memory of the incest intact but they would realise who was responsible. Instead they were left with sperm oozing out of orifices, wondering how it got there.

Having sworn Ron to secrecy they boarded the train and entered the compartment. Harmony peered over the text book she was reading, [Being a muggle she felt duty bound to study harder than any other student]. "Hi guys. Looking forward to the new term?" Her large, slightly myopic, eyes smiled.

"Certainly are," replied Ron as they sat opposite her. They exchanged a few words before the express gave a little jerk and started to roll on its journey. Harmony raised her book to her eyes and continued with her reading. She wore her skirts shorter these days, a couple of inches above her knees. Her uncrossed legs were shapely with slim ankles. Barry waited until students stopped moving about. Some glanced into their compartment but moved on, leaving the three of them with their privacy.

The train had reached the suburbs of London before Weasel saw Barry slip his hand inside his jacket and withdraw his wand and point it at Harmony. The movements were too rapid for Ron Weasel to follow let alone memorise. He heard Barry mutter under his breath.

What he didn't catch was the incantation, "Inhibitios Departo." He watched Barry tap his own genitals and mutter, "Penis expando." He felt Barry's wand tap his own groin. For a few seconds nothing happened, then he was aware of his cock growing longer, thicker and stronger. He watch amazed as he just kept growing and growing. A full nine inches lay obvious down his trouser leg, Barry was the same.

Harmony's eyes scanned the text of the, 'Book of Advanced Potions' When she felt a little tingling on her nipples, it felt pleasant. She glanced down at her small breasts and saw they were pushing out the material of her dress. The tingling spread from nipples to areolas and spread through her swellings. She felt the same tingle start in her vagina, spread to her inner labia, her outer labia, she gave a little gasp and crossed her legs as it reached her clit. She looked over her book, her two closest friends were watching her closely. She needed them desperately. She put the book down and leaned to one side, placing one foot on the seat her legs wide apart. She saw the eyes of her friends drop to her lemon panties and the growing damp patch. Her eyes widened when she saw their erections, her tongue ran along her bottom lip.

The boys watched her licking her lips as she looked at them with hooded eyes, a small smile on her face. Her hands started to squeeze her own tits and playing with the nipples. With a grunt of impatience she unbuttoned her dress and shrugged it off her shoulders. Her hands went behind her back and unfastened the clasp of her bra which she placed on the seat beside her. The boys watched her close her large eyes and kneading her breasts, playing with her pink nipples. Barry raised his wand and made a circular motion. Harmony opened her eyes as she felt her breasts grow to a decent mouthful. The wand did another circular motion, her breasts grew to a decent handful, a little squashy with the tips up-tilted.

"Barry Potter, what have you done to me?" There was a giggle in her voice.

" Advanced the development of your tits to your twenty-first birthday, Harmony, but left the rest of your body at the age you are now."

Her tingling was becoming intense and had spread to every inch of her skin but going deep into her very being. Her eyes flicked between the two boys enjoying there lustful stares, occasionally dropping to the lumps in their trousers. As she watched, Barry slid down his zip and pulled out a magnificent penis, so thick and long. He pulled out his balls, they were huge and looked ready to burst. She couldn't hazard a guess how much juice they contained. Ron Weasel's quickly followed. She couldn't chose between them, but perhaps Ron edged it because she had been attracted to him for some time. They were stroking them, stretching the skin. Huge purple glands shone as if polished. Her hand slipped into her panties, watching the boys' eyes follow her action. She groaned as her finger touched her clit.

Ron watched her fingers in disbelief as they moved in her pink wetness. Harmony and he had grown closer in the last term, they had even kissed. She had an aloof nature, bordering on the snobbish, this display was exciting tempered with a little disquiet that Barry was also witnessing  her actions. He quickly dispelled his jealousy. He could have stopped it on the King's Cross platform but didn't.

"Don't just...sit there...you two,...help me," Harmony ordered through gritted teeth. They moved over and sat on either side of her. Her dress and panties were removed hurriedly. They held her legs up, pulling them apart. They peered down at her pubic hair and vulva that glinted with wetness in the sunlight. It was the first time either boy had had the chance to study a pussy outside of muggle magazines. This wasn't any pussy, it was the aloof Harmony's pussy and all the more facinating for them to see.

Barry's finger softly touched Harmony's clit, exploring its length and hardness. She gave a little gasp and her pelvis jerked. Ron's forefinger slipped easily into her lubricated vagina, pushing in up to the knuckle. A quite groan issued from her husky throat. Her arms went over the shoulders of her helpers, her head went back, wide eyes staring as the carriage ceiling as she gave their administrations her full concentration. Barry's finger stroked along her clitoris, sometimes holding it and pushing back the hood.

He moved his finger in a circular motion varying the pressure and tempo. Ron's finger produced a faint squelch as it moved in her body, feeling her responding to him. He inserted a second finger into her tightness, the squelch became louder. Ron put his fingers in his mouth and sucked, giving Barry a cheeky grin. Harmony placed her hands on their heads and pulled their mouths to her breasts before searching for and finding their cocks. Two pairs of lips enclosed her nipples and sucked; her body shuddered.

"Thank you boys, thank you so much." Her gasping voice uttered. Her body started to tremble, her moans turned to squeaks. Ron moved his dripping fingers faster. The squeaks turned to loud squeals and her young body shook, her breathing ragged. Her hands stopped stroking their cocks and gripped them tightly. "Work my cunt boys, work that cunt." A damp patch appeared on the seat as her juices ran down between her plump buttocks. Her lovers, shocked at her language, slurped at her tits as her orgasm reached peaks of bliss she had never produced by herself. Harmony's powerful feeling started to abate. Her breathing steadied as the boys relaxed and grinned at each other. "Thank you guys, that was special." Her hands started to massage their thick shafts again. She looked at both cocks smiling. She made eye contact with Barry, his glasses had slipped down his nose. "Go back to your seat Barry. I want to suck your prick until your spunk fills my mouth."

He sat opposite her, his rampant cock oozing. She stood up, planted her feet apart and arched her slim, flexible back, buttocks rearing in the air. She licked the pre-cum of his knob. Ron saw the expression on Barry's face as his girl friend's tongue circled his gland. He though he should have gone first. Barry pushed her long, fair hair behind her ears so the view of her mouth wasn't obscured. Ron's eyes went to the hair fringed labia and the small dark portal of her vagina. She looked over her shoulder at him smiling wickedly and wiggled her rump. "C'mon Ron, I want you o be my first. You do want to fuck me don't you Ron? I want you to fuck me. I want your cock in my cunt, deep and hard"

Ron stood behind Harmony trembling watching her head bobbing on his friends cock. He gripped her hips and positioned his throbbing gland just below her puckered anus and pushed. She was impossibly small, 'I'm never going to get it in', he thought. He pushed some more and saw her stretch. Her mouth left Barry.

"OH my God!" she gasped.

"Am I hurting you Harmony?" he asked anxiously.

"Of course you are, but it's a nice hurt, don't stop." She groaned as more pressure was exerted. She felt her inner lips pulled in with the friction and tried to relax. She thought she might rip. Just when she thought he would have to stop there was a little jerk and his knob passed her pelvic bone.

Ron felt her warm, moist flesh surround his shaft. He was dizzy with emotion. The walls of her vagina seemed to be exploring him. His shaft penetrated her slowly until it checked against her hymen.

Harmony was still ignoring the cock an inch away from her mouth. "One good push Ron Weasel and you will make me a woman. Take my virginity Ron, take it." She felt the extra pressure, then she was breached. She gave a squeal at the sharp pain that disappeared as almost as quickly as it had arrived. The rock hard shaft, that became thicker towards the root, continued its momentum until she felt the pendent balls on her buttocks. Harmony felt well and truly corked. Her mouth descended over Barry Potter's weapon.

Ron was in seventh heaven. His weapon was in Harmony at last. He withdrew slowly seeing his shaft glistening pink with her juices and blood. So tight, her inner lips reappeared as he pulled out of her. He had fantasized about this moment when he masturbated himself to sleep but never imagined it could be this good. He plunged back into her with a grunt, his groin slapping on her buttocks.

Harmony staggered with the thrust, her tits swinging. She too found reality better than her fantasy, for starters she never imagined a threesome with her two favourites. She braced herself more firmly ready for meet the next lunge. With a big cock in her mouth and another plugging her vagina and her body enjoying the afterglow of her orgasm, it didn't take long before she felt the distant ripples of another one building. She glanced up at Barry's face and saw with satisfaction the intense luck of lechery as he watched his tool being sucked.

Barry watched Harmony slurping on his rigid member, she was actually drooling, her spittle dribbled down his shaft. Her animal noises became louder and she used the cock to stifle her cries of joy as her orgasm grew in intensity. Ron's grunts were audible as he plunge into her again and again with loud squelches. Barry saw her eyes open wide as if terrified and roll back so only the whites were visible. Although the three of them were inexperienced, some things come naturally. Harmony pushed back to meet Ron's thrusts while Barry teased her nipples.

Ron felt Harmony's vagina convulse round his shaft. She was dripping fluid onto the compartment carpet. His balls gave him little warning before he enjoyed the ecstasy of his sperm rushing along his shaft and splattering into the welcoming vagina. He gasped and groaned as jet after jet of his juice bathed her insides. Barry's spell had given both of them a copious reservoir of sperm and permanent erections. Ron kept on thrusting until he heard Barry cry and Harmony was forced to swallow rapidly to take in all of his gushing.

The boys changed places. "You've got to teach me the spell Barry," pleaded Ron.

"Sorry Ron, no can do," he replied a his cock pushed into the girl, "but you don't need to know the spell. Court Harmony in the right way and you can enjoy her as often as you like. Isn't that right Harmony?"

"Of course it is," she replied, "fucking is lovely."

"It wasn't just Harmony I was thinking of," Ron said looking a bit guilty, "I want to fuck my sister."

"I will cast the spell for you Ron, but it will be my turn to go first."

"You've got a deal," agreed the grinning Ron.

The fuck fest lasted until the approach to Warthogs forced them to disengage. The carpet was slippery under-foot with the sperm that had flooded out of Harmony. Barry waved his wand and her tits reduced to their normal size. She started to dress, preferring her tits larger. The wand tapped Ron's erection. He watched his cock turn limp and shorten. The matted pubic hair at its base dried and cleared. The carpet returned to normal, there was no sign that anything untoward had taken place. Barry waved his wand at the fully clothed Harmony, her head fell to one side in a deep sleep.

"She will have no memory of being fucked, Ron. All traces of our spunk are gone and her hymen is repaired, she is a virgin again."

Harmony awoke immediately, blinking in the light. She looked at her watch." I'm sorry boys. That was rude of me, I've slept for over two hours. I hope you were not too bored. I still feel tired." A puzzled look came to her face and she looked down at her lap and squirmed in her seat. She picked up her abandoned book.

"Any good potions in that, Harmony?" asked Ron with his cheeky grin.

"Lots and lots," she answered smiling. "There's one using your own urine, herbs, rabbit blood and a ravens egg that stops others gaining control of your mind and body." Her smiling eyes  disappeared behind the book.