With a yawn I pull back the bedroom curtains, squinting as the strong June sun came streaming in through the windows. I like summer in England, I look forward to it, it’s my favourite day of the year. My name is Bobby Priest and today is my birthday. Mum and dad had driven out to the fens for a long walk and wouldn’t be back until late. I was going to get the boys over to play some loud metal and down some beer. Girly chatter and squeals from the garden told me that Jackie had other plans.

Peeking from the bedroom window I saw that the garden was full of girls. Due to the warm weather, they were wearing tiny skin-tight sleeveless halters and small shorts or briefs. As a growing lad, I was of course interested in girls. However I preferred them my age not kids a couple of years younger or less. Only these weren’t ordinary girls, I pondered as a couple threw themselves into a perfect rock steady handstand. They were from my sister’s gymnastics club, all of them serious athletes with a steely determination to compete and win at the highest levels. Dedicated with the tunnel vision focus of a professional these girls worked their bodies hard from an early age in order to achieve perfection and therein lay my problem. You see I had discovered that I had a fetish for women with fit muscular bodies. I love the look of a feminine looking woman who can flex rock hard muscle. Why was that a problem? Well out in that garden were a dozen or so of the counties’ best female gymnasts, scantily clad super-fit teenaged girls with bodies that would make many female bodybuilders green with envy performing exercises of extreme flexibility and stamina that would give boys like me a raging hard boner in next to no time.

It was embarrassing enough that younger girls could give me the raging horn but these were fresh-faced wide-eyed girls with bodies that no young girl should possess. Worse of all it was my little sister, Jackie, who had awoken these feelings when I wrestled her [BOBP#1] and she totally humiliated me in front of my mates and then in front of the whole school. That’s when I discovered how overwhelmingly strong a female gymnast is and, to my shame, how turned on I was by the experience.

A creak of the floorboard outside my open bedroom door and I whirl around to find my sister standing there with a wide smile upon her face. “Spying on the girls, Bobby?” she spoke in a soft voice. Two years younger than me, Jackie only stood 5’1” to my 5’9” but was built like a small tank. As she stepped into my room without asking I felt intimidated by her short stocky athletic build. “I ... I wasn’t” I cursed myself for sounding nervous. Her smile got wider. Jackie looks so sweet when she smiles at you that you find yourself smiling back. Long golden hair swept back behind her left ear while tumbling softly caressing the right side of her face. I tried to remain calm as she approached with a calculating smile. Jackie reached out and ran a finger along my chest leaving a tingling trail as her small blue eyes locked onto mine from atop a small slender nose. “You sure you weren’t about to jerk one off” she said softly. “Don’t talk like that!” I snapped shocked by such language from my little sister, feeling my face blush at her accusation. Jackie stepped into my personal space and I instinctively stepped back to find myself against the bedroom wall.

You are probably wondering why I am so nervous of my younger sister who is a pretty little thing. She might be short but she has that classic gymnast build. You know, the one with the huge broad shoulders with the large trapezius muscle sloping from her neck and the massive rounded shoulder caps with thick heavyset arms. This heavyset upper body tapered in a definitely feminine manner to her waist before curving back out to her hips. Her body was the female equivalent of a heavily armoured truck developed through many years of competitive gymnastics. It was all the more intimidating due to a tight Lycra halter and a skimpy pair of briefs which showed off big solid arms with a thick vein running down them; a deeply chiselled six-pack abdomen; and big heavy strong looking legs. I on the other hand am not the sporty type which made me feel strange confronted by my short hulking younger sister.

“What the?” I gasped as Jackie aggressively thrust her crotch forward so that it was pressing hard against my groin. It was strange to be pinned up against a wall by a girl’s crotch, oddly intimidating and aggressively sexually dominant. It was something a girl shouldn’t do, certainly not a sister to her brother. I’m just a guy and embarrassingly my body began to react in a manner that it shouldn’t. Her right hand cupped my chin forcing me to look at her, with a solid swell in the middle of her upper arm. “Don’t pretend you don’t like me touching you there” she teased “You are coming outside into the garden, Bobby. I’ve got a present for you”. “No, stop that!” I gasped as her crotch began rubbing against me and I stiffened further. “Or you can stay here and I will make you cum in your pants. You know you can’t stop me” she chuckled. My dick actually hardened with those words and part of me wanted to say “yes please”. Most boys would in my position but then she wasn’t their sister. She might look all sweet and innocent but I knew that the brat would have no hesitation in embarrassing me like that. “OK I’ll go down to the garden” I replied hoping to get this over with quickly so I could call the lads over. She actually looked disappointed “Never mind. Maybe later” she sighed. “Orrrr!” I moaned out loud as she pressed her crotch hard against me and gave one large thrust upwards riding my stiffness like a monorail track. I sweated profusely as I nearly came prematurely. “Cluck cluck” she clucked with a cheeky smile as she tugged my right cheek with her hand while withdrawing her private parts.

Feeling terrible that I responded to her like that I followed her downstairs. Looking at Jackie from behind, she had the kind of exaggerated hour-glass figure that on female bodybuilding websites would leave me drooling. Her heavy broad shoulders with the big sloping traps tapered dramatically to a slim waist before curving over her hips. As she walked, her wide back rippled with large irregular muscular shapes like a rocky contour map. Lowering my gaze her tight rounded buttocks were clad in a skimpy pair of briefs cut disturbingly high on the hips. Oh God! Female gymnasts have the sexiest arses imaginable especially when clad in clinging Lycra. The rigid dirigible forming inside my trousers made me feel ill about how my sister’s densely-built body could turn me on.

“Wotcha Bobby” “Hiya birthday boy” a chorus of girly welcomes greet me as I step outside. A dozen or more teenaged girls crowd around me surrounding me with a sea of short girls who are on average two years younger than me but their strong power-packed bodies prevented me of thinking of them as annoying little brats. “Who’s your favourite Bobby?” “Anything you fancy?” Everywhere I look are thick strong bodies with broad shoulders, veined arms and chiselled six-packs. These girls are showing a phenomenal amount of muscle which makes me feel inadequate as a boy yet turned me on like crazy. There were quite a few good lookers too that I fancied if only they had been a couple of years older. Most had wide exaggerated hour-glass figures and some were pleasingly buxom. I often went to Jackie’s gymnastics competitions to see the girls prancing around in sexy Lycra leotards clinging to their fit sturdy bodies like a second skin and cut high upon the hips. That was sexy enough and kept me up all night replaying every sensuous curve and athletic move in detail, but seeing them so close that I could have reached out and touched them while they exposed vast amounts of skin was a whole magnitude more arousing. I didn’t know where to put my eyes and couldn’t stop staring openly at the amazing bodies all around me.

“I need to put more lotion on before I burn” Jackie remarked. That was another thing, the girls had applied sun tan lotion to protect themselves from burning. The sun reflecting off their glistening oiled bodies emphasised the remarkable muscularity of these young determined athletes. I had to admit their bodies were fit and sensational, chiselled with hard defined muscle like pint-sized statues of near-naked amazon warriors from times long gone with perfect musculature. I was in muscle-topia. All around me were smiling girls with very broad shoulders for their short height, capped with hard prominent rounded balls, faintly striated and with deep indentations leading to their upper arms. I was more familiar with these girls competing clad in skin-tight Lycra leotards but today they wore sleeveless halters that barely covered their breasts and left their arms bare. There was so much firm, hard shapely bare flesh around me that I felt inadequate and uncontrollably hard beyond the point where I could hide it. These girls had arms which were shockingly defined. Brawny and sinewed, the front of each biceps was adorned by an unnervingly prominent vein running down them. The back of their upper arms were solid and thick with well developed triceps. Forearms were phenomenally shaped like those of a tennis pro, tapering from very slim wrists to become very thick at the elbow with hard broad slabs criss-crossed by a network of vine line creepers.

As the girls came up to wish me a happy birthday I couldn’t help marvelling at their amazing taut toned stomachs. “What’s wrong Bobby?” It was Treena, a girl that Jackie tried to set me up on a date with. I refused finding her plain-looking and the spectacles she normally wore and braces put me off. But now as she stood before me in halter and briefs with her hands on her hips my dick lurched hard at the sight of a phenomenal well-defined washboard stomach. As with the girls around her, even without flexing, a deeply chiselled grid-work of tight rock hard interlocking slabs cut up her firm belly. Orrrr! I couldn’t stop my trouser-tent twitching in pure lust. Her arms and legs looked sensationally developed too and I regretted telling Jackie that I wasn’t interested because right now I had a dreadful urge to whip it out and run it up and down that deep vertical groove in the middle of her dense taut abs until I blasted boy-cream all over them. “Wotcha looking at Bobby” she giggled causing those amazing abs to ripple like a belly dancer. Beneath her abs, a tantalising V shape vanished into her briefs. Devil’s Horns Jackie had called them and I could now see why as I struggled with the temptation to pull down her briefs to reveal the rest of it. My eyes fell to her legs. Relatively long and slender for her height, they weren’t as thick as my sister’s. However they had the sleek sensational curves imparted by developed calve muscles, hamstrings and thighs. Oh my word! I never realised this gawky plain girl had such a sensational body. As she turns around to greet Jackie, I am staring at a rippling back shaped like an inverted triangle. The back of her triceps are highly defined resembling bulging scissors on the backs of her slim arms. I was gob-smacked by the sleek level of muscular definition on this petite girl. “Hi Jackie. I was just wishing Bobby happy birthday” she said looking back over her shoulder at me. “Yes Treena. I can see he liked that” my brat sister replied pointedly looking at the front of my trousers.

Jackie stepped forwards with a big wide smile that instinctively made me smile back as she stretched out her right hand. “Happy birthday big brother” she said so cheerfully that I automatically put my hand in hers. Her fingers enfolded the back of my hand as our thumbs interlocked. I was surprised by how firm her handshake was then was wincing in agony as the pressure kept climbing mashing my fingers together. My younger sister kept smiling while her small hand crushed mine until the bones were grinding. “Argh OK that’s enough” I gasped and tried to prise her hand away. To my horror Jackie simply swapped hands uncrossing our arms grabbing my left hand with her right and vice-versa then began to push back both of my hands. I was shocked to find myself in a finger-lock trial of strength with my little sister in front of a whole group of girls. No way! I wasn’t going to let the blonde dwarf get the better of me this time. Gritting my teeth I pushed back with all my might to force down her arms so that I could then twist them and cause the brat some pain to teach her a lesson. I was shocked to find that her arms were like iron pistons, completely solid and unmoveable despite putting all my strength into it. To make matters worse my own arms were being forced down by a steady force. The only sign that she was putting in any effort was the ominous swelling in her upper arms like someone had taken a bicycle pump to them. The biceps veins had also became more prominent and quite intimidating. “I’m really strong aren’t I Bobby? Stronger than you” she teased while her face shone sweetly with no signs of exertion. Jeez! I was really struggling. No she can’t be doing this to me! She’s not much more than a kid, she can’t be stronger than me. How could I let her beat me? Oh Jeez look at her arms! They had become so solid and bulging I felt weak just looking at them. To my embarrassment my dick was getting harder at the sight of those gently swelling muscles and I had no hands free to hide it. Jeez stop it Bobby! Get a grip. The prominent veins running over her swelling biceps taunt me as her arms force me down. Her grip is so strong crushing my hands that I’m whimpering as I begin to sink down before her.

My face was level with hers when Jackie suddenly pulled my arms wide with shocking force like they were wishbones, pulling my chest tight against her bust. I was staggered to find myself partially crouching before her with my arms pulled wide with her breasts pressing through her halter against my chest. Being stretched across a girl’s bust was a new experience for me which I naturally found exciting even though this was my sister. Jackie’s blue eyes stared continually into mine, never averting, always smiling. It was not the gaze of an adoring younger sister it was an exultant challenge of her physical dominance. Holding my hands she bent her arms upwards at the elbow. Ulp! Her arms grew thicker, expanding twice as thick in the middle then continuing to bulge rapidly even more. At first they became the size of small softly rounded balls of hardness rapidly growing taller and more rugged becoming formidable peaks of feminine power. Jeez! I was gob-smacked by their sheer size. I had seen her flex before but that was some time ago. Now I nearly choked. Oh Jeez how could they be so big? My dick stiffened uncontrollable confronted so intimately close to such sheer power. They were so thick and massive. They were fecking huge. Oh feck! How was a boy expected to handle that? It wasn’t fair! Jackie’s biceps were short in length but had swelled to rocky dense peaks of an unexpectedly massive height for a girl of such youthful appearance. Oh God! She’s too strong! My arms were shaking as I poured everything I had into them yet still her arms would not budge a single millimetre. It was like trying to push over a lamppost. “Come on Bobby, you’re not even trying” she teased still looking cool and calm. The corners of her lips rose “I’m a gymnast Bobby. My body is at the peak of physical perfection” she gave me a knowing wink of amusement as I began to weaken in trying to oppose her arms. Standing there with her arms raised and biceps bulging as if made of steel she continued to pull me tight against her. “I have much harder muscles than you, larger too, and they get a lot of practice. You don’t stand a chance brother dearest. I’m more than you can possibly handle so you might as well beg to worship my big muscles” Her grinning angel face moved closer as she lowered her voice to a whisper “I know that’s what you really like for your birthday”