Lil' Sister Got Super-Sized!  Chapter Three: Dressed for Excess
by Gorgon
Third part of a new muscle growth story
        
    Less than an hour ago lil' Lucy Billings was an ordinary eleven year old 
girl.  But little did she know, her father had slipped some experimental 
muscle growth serum into her brother's spinach last night-- spinach that her 
brother Rudy didn't eat, but she DID!  After messing around with her 
brother's weights this morning, Lucy's body swelled up with monstrous 
muscles!  Now she looks like a short (but massively built) heavyweight 
bodybuilder from the neck down-- and a sweet-faced eleven year old girl from 
the neck up!
    She had just showered and her chiseled body still glistened from the 
water.  Lucy was amusing herself, flexing for her gangly sixteen year old 
brother in his room, and watching him drool over her power-packed physique.  
Striking her most muscular pose, a massive crab-flex, Lucy's titanic muscles 
expanded a little too much and her bath towel popped off and fell to the 
floor.  Lucy giggled as she covered herself with her hands and raced across 
the hall to her room to get dressed.  Rudy just sat on his bed in shock, 
sporting a raging erection between his legs.
    In her room, Lucy pulled a pair of her panties over her large, firm, 
muscular glutes.  There was no way she was going to get her big, thick legs 
into any of her pants or shorts now.  But she was able to slide into a pair 
of stretchy bicycle pants.  She marveled how they showed off every curve and 
sinewy striation of her thighs.  She flexed her upper legs and her calves, 
staring in awe at how powerful they now looked.
    "Well, that takes care of my pants," Lucy said to herself, while admiring 
her new pumped-up body in her full-length mirror, "But a shirt is going to be 
one heck of a problem!"
    She laughed as she struck some upper body poses, making different muscle 
groups swell up and down with each flex.  She couldn't wait to go to school!  
She had to be the strongest kid in the world-- girl OR boy!

    Meanwhile, still in his room, Rudy had stripped down to his underwear and 
was stroking himself repeatedly.  He just couldn't believe what he had just 
seen this morning!  Muscle after muscle growing and growing and growing all 
over his sister's little body!  He tried very hard to imagine someone else's 
head on her body... He was close to pleasuring himself when there was a knock 
on the door.
    "I'm BUSY!" he yelled out, his voice squeaking.
    "Rudy?" came his sister's voice, "Can I come in?"
    Rudy quickly pulled his underwear up and raced over to the door.  His 
boner was now in full effect, pulling the elastic of his white cotton briefs 
well away from his waist.  But all he could think about was seeing his 
sister's super-buff body again!
    "Yeah?" he tried to say nonchalantly as he opened the door.
    When Lucy saw her gangly older brother standing there in his underwear 
(and his erection), she couldn't stop giggling.
    Rudy, on the other hand, couldn't stop staring!  His eyes ran up and down 
Lucy's physique.  She was wearing pink sneakers, white bunched up socks, 
skin-tight bicycle pants, and a button down shirt that was stretched and 
strained over her power-packed upper body.  Seams were ready to snap!  
Sleeves only came up to her muscular mid-forearms!  Gaps of pumped-up pink 
flesh showed through the spaces between her straining shirt buttons!
    "Hey there, stick-boy," she giggled, "Can I borrow one of your shirts?  
None of mine seem to fit anymore."
    "W-w-wow!" stuttered Rudy, "Um... sure, help yourself."
    "Thanks," said Lucy with a wink, "First let me get out of this old thing."
    Lucy relaxed and took a breath.  Rudy watched in shock as her big, broad 
chest expanded!  Like falling dominoes, Lucy's top three buttons popped off, 
one after another, exposing her muscular pecs in all their humungous glory.
    She raised her left arm and slowly flexed it.  Rudy gulped as he watched 
her bicep rise and rise and rise.  There was a tearing sound as Lucy's shirt 
ripped revealing more and more muscular flesh!  Soon, her entire arm burst 
through her sleeve with a jello-ish jiggle, which then firmed up into a 
diamond hard bicep peak!
    "Holy shit!" Rudy gasped!  He was about to lose his load right there.
    Lucy laughed at how much her "big" brother was enjoying her little muscle 
show.  She gestured to her right arm.
    "Wanna see that again, scrawny?" she asked.
    "P-p-please!" Rudy stuttered.
    Lucy teasingly held up her right arm.  With even more deliberate 
slowness, she raised her arm, ready to flex.
    With her muscular left arm, still surrounded by the tattered remainders 
of her left sleeve, Lucy took one of her brother's hands and placed it on top 
of her plump right bicep.
    "Here," she said with a smile, "Let's make this a 'hands on' experience."
    Rudy's hand trembled as he felt Lucy's bicep swell up and up and up, 
pushing his hand higher and higher.  As the tearing began again, he could 
feel the straining fabric of Lucy's shirt sleeve give way, exposing warm, 
firm, bulging flesh!  Soon, all the sleeve was gone, sliding away under 
Rudy's sweaty palms, and he was left caressing a rock-hard mass of bulging 
bicep!
    With a firm (yet gentle) grip, Lucy removed Rudy's hand.  She turned 
around and expanded her gigantic back muscles, bursting through the remains 
of her poor shirt!  She cast off the torn fabric and sauntered over to Rudy's 
shirt drawer.  She pulled out one of Rudy's large t-shirts-- a Rams shirt 
they bought at the last game they went to. 
    "Here," said Lucy, "Help me get this on."
    "O-o-okay," stammered Rudy.
    The shirt was large and baggy over his straggly body, but on the new 
Super-sized Lucy, the shirt was sliding on like a tight second skin!  Rudy 
grunted and strained to pull the shirt down over Lucy's rock-hard physique.  
His hands dragged down along Lucy's massive, tapered shape!  She was so THICK 
and so HARD it boggled his imagination!
    He pulled and pulled and pulled, but the shirt physically couldn't go 
down any further.  It stopped just shy of her armor-plated, six pack abs.  
Her arms completely filled out the shirt's short sleeves and hung at her side 
like massive sides of beef!
    Rudy stepped back and looked at his sister in shock.  She looked like a 
four and a half foot pro-linebacker!  She was now an eleven year old 
super-jock!
    "That was fun!" said the spunky little amazon, "Now it's my turn!"
    And with that, she reached out, grabbed Rudy, slung him over her shoulder 
and started carrying him over to her room.  His erection pushed against one 
of Lucy's meaty pecs.  He was so ashamed!
    "What are you doing, Lucy?" he asked in fear.
    "I'm returning the favor, big brother," she said with a hearty laugh, 
"You played dress-up with me, now I'm gonna play dress-up with you!"

    Lucy closed her door and then put Rudy back down on the ground.
    "Hmm," she said, "This is gonna be tricky.  I may be BIGGER and THICKER 
than you, but you're still taller...  Get on your knees."
    Like an obedient slave, Rudy immediately dropped to his knees.  Now Lucy 
and he were eye to eye.  Brian gulped again.  She was so much bigger than him 
from this vantage point... it was overwhelming!
    "Good, boy!" she laughed, like she was playing with a dog, "Now stayyyyy!"
    Lucy went through her top drawer and pulled out some clothes along with a 
matching Ram's T-shirt.  But it was her old t-shirt, a shirt meant for an 
eleven year old girl!
    "Look!" she said with glee, "We can be twins!"
    She laughed as she dragged the shirt over her taller, 16 year old 
brother.  With her amazing strength, Lucy had no problem squeezing Rudy into 
the tiny shirt.  There was nothing Rudy could do.  How could he argue with 
his titanic little sister?
    She picked him up and sat him down on her bed.
    "Now for some clean underwear!"
    Rudy watched in fear and awe as Lucy reached down and grabbed the elastic 
band on either side of his boner!  His eyes widened as Lucy's arms swelled up 
with muscle as she strained against the tensile strength of Rudy's underwear. 
 With a mighty rip, the cotton briefs tore off, making Rudy's erection spring 
forward like a jack in the box!
    "Oh my!" he gasped.
    Lucy pulled up the next article of clothes, a pair of her tiny panties.
    "See?" she giggled, "We'll have twin outfits in and out!"
    "Lucy!" Rudy yelled, "Cut it out!  NO!"
    Lucy laughed and laughed at how powerless Rudy was before her.  With one 
hand she pushed him down, pinning him on her bed.  Then she reverse straddled 
his chest, putting her big, round, bulbous glutes on top of his ribs.  All 
Rudy could see was her muscle-swollen back and broad, rounded shoulders as 
she manhandled his flailing legs.  She forced the little-girl panties on his 
sixteen year old body.  The tiny panties cut across his boner, and he felt 
that the pressure was going to make him EXPLODE!
    But that wasn't the worst of it!  Next, Lucy pulled out a pair of 
matching bicycle pants!
    "Oh, stop squirming!" she scoffed, "If I can get a pair of these over my 
big ol' legs, your bony ones shouldn't be a problem!"
    As soon as she finished snapping them on, Lucy got off Rudy and propped 
him back up on his feet.  Feeling Lucy's muscular body writhe on top of him, 
the pressure of the stretchy bicycle pants, and the restricting panties...  
Rudy's erection felt like it could "blow" at any second!  It trembled and 
shook.
    Lucy had the two of them pose in front of her full length mirror.  She 
giggled at the site of herself about to burst out of her big brother's 
clothes... and her big brother about to burst out of hers.  She poked at her 
brother's pale, flabby stomach, and then moved her hand up feeling his 
non-existent chest.
    "Here" she said, taking his hand in hers and running it up along her 
bulging abs, "Check out what a body is supposed to feel like!"  
    As Rudy's hands went further and further along the tiny amazons frame, he 
could feel muscle after muscle till finally she was messaging his hand into 
her thick, meaty pecs.  She giggled as she tensed her chest, making it swell 
up FIRM and HARD in Rudy's grasp!
    It was all too much!  Rudy ejaculated-- squirting all over the mirror in 
front of them!  Lucy burst out laughing!
    "Aww!" she clucked, "Did my big brother have himself a little accident?"
    "Kids!" their mother called from downstairs, "The bus is outside!"
    "I-I-I gotta go!" Rudy stammered!  He couldn't wait to get out of that 
room!  He 'tucked himself' into the bicycle pants, raced downstairs, grabbed 
his shoes, jacket, and backpack and was out the door.  His mother looked on 
in shock!
    "Honey," she said to her husband Buck, "did you see what Rudy was 
wearing?!"
    "No dear." said Buck behind his sports page.
    "He was practically bursting out of his clothes!"
    Buck was thrilled!  He took this as a sign that his plan was working!  
That experimental growth hormone he slipped in Rudy's spinach last night was 
finally taking effect!  His son was growing into a big jock, just like his 
old man!
    Just then Mr. and Mrs. Billings heard the stairs creak, as if under some 
tremendous weight.  Suddenly Lucy bounded around the corner.  She waved 
good-bye to her parents as she headed out the door.  She had quickly put on a 
baggy pair of her dad's sweat pants and a sweat shirt.  It covered up all of 
her bulging, new muscles...  but there was no hiding her immense new girth.
    "Is it just me," said Buck, who never really paid that much attention to 
his eleven year old daughter, "But is that girl of ours porking out?!  Look 
at her!"
    "She's just a growing girl, Buck.  She's just going through some awkward 
changes."
    "Well, I say we send her to a fat farm... or a gym or something!"

    On the bus, no one really noticed how wide Lucy had become... since 
everybody was too busy pointing and laughing at her ludicrously dressed 
brother.  Lucy giggled mischievously.  She just couldn't wait for the perfect 
moment to reveal her new super-muscle-bulging physique to the kids at 
school...

TO BE CONTINUED