Shining Armor had always prided himself on his appearance.  It was an early morning and the hot shower always made for a relaxing, if not predictable means to wake himself up for work.  He had taken a moment to check in on his baby sister as part of his routing before before disrobing to get his day started in the bathroom.  He knew she would toss and turn in her sleep, but she must have been in rare form the night before as the tight t-shirt she insisted on wearing was rolled up well beyong her  coller bones.  Her panties had also seemed to roll down to the midpoint of her thighs and her hands were resting between her legs as if she was halfway trying to cover herself up or halfway trying to pull them back up.  He let out a brotherly smile as he modestly rolled her panties back up her thighs as she let out a moan and rolled over.  Her panties still radiated the heat from her body and seemed overly moist compared to the mild environment she was sleeping in.
He decided not to press his luck and let her bare chest remain exposed as opposed to having to wake her up to appease his shyness as her shirt rolled up well beyond her nipples.  He felt his cheeks warm as took an extra moment to gaze at the buds of his sisters chest as they seemed to bloom and pierce the morning light.  He unconciously looked over his shoulder and bit his lip.  He knew nobody was looking but he couldn't help but feel a sense of ambilvalence and shame as he ran his thumb over his sleeping sisters nipples.  They felt hard and warm compared to the soft miniscule skin that surrounded them.  He felt a tightness in his shorts as she let out a moan and brought her index finger to her mouth as if to bite it.  The scare was short lived however as she rolled over and returned her hand between her thighs.  
   Shining Armor shut the door to the bathroom and felt an inexlplicable sense of relief. He knew nobody could observe him, but there was still a pang of excitement that seemed to linger about thinking of his sister in a state of undress.  He had seen and even felt other mares bare breasts before.  Twilight's were small and undeveloped compared to the mature mares that he had experienced before.  He felt his cock pushing against the towel around his waist as he felt his cheeks warm again.  A sense of chagrin overcame him as he recollected his fingers rolling over his sister's exposed buds.  He dropped his towel and gave himself a compulsory look in the mirror.  He flexed his abs and gave a nod of self satisfaction.  He sucked in his torso and admired the sight of himself in the mirror.  The recent memory of his sister in bed remained in the back of his mind as he noticed the weight of his cock as it swayed between his legs.  He always had a sense of pride while admiring his size in the mirror during his morning routine.   The morning's experience with his sister had engorged  him this morning well beyong the medial ring of his cock and he felt himself blush as he watched his cock rise in the mirror.
   His own harndess, mixed with the thoughts of his sister almost brought him to a state of full blown erectness.  He shook his head to rid himself of his excitement and rolled the faucet handle of the shower.  The hot water rolled over his chest and flowed down his abs.  His cock was still pulsing as the hot water rolled down its length.  He took a breath as it softened between his legs.  He lathered up the soap against his body as he attempted to ignore the feeling of mass between his legs. Just as the heat took over and he almost allowed himself to relax his adrenaline spiked as he heard bathroom door open and slam shut as Twilight entered the bathroom.
   The curtain of the shower was the only boundry between Shining Armor and his younger sister Twilight right now.  He peeked out the corner and discovered in her sleeplessness that she had completely eschewed the t-shirt that covered her bare chest before.  She didn't have the age to possess the developement of the mares he had been with before but seeing her bare immature breasts returned the weight that was belying his brotherly feelings between his legs. He watched as she bent down and removed her panties before hopping up to seat herself on the toilet, totally naked.  He watched and could only feel a sense of confusion, matched only by his sense of excitement as he watched and listened to his sister let loose a flow of urine into the toilet.  As the last drops of her stream dripped he almost felt a sense of contempt as he felt the full size of his cock as it throbbed in his hand.  His whole body tensed as he stroked its lenght before he felt an adrenaline surge as his own naked sister pulled open the curtain of shower.
   Twilight yawned as she threw open the curtain of the bathroom shower.  She had already stepped inside before she noticed the hot water was already running and she wasn't the only one occupying it.  She knew the smell of her brother.  Even in her daze she knew he was already in shower she was currently standing in.  She knew it was him even if she wasn't familiar with the warm rod of flesh pressing between her shoulder blades.
   She turned to face her brother.  The warm pressure between her shoulder blades was now replaced by a warm pressure between her breasts. Even though she was less than half his age and a third of his size she felt a sense of titilation in her stomach.  She had seen her brother naked before but this time a part of him seemed, bigger.   A part of her brother that she had seen before had grown and was now poking her in the chest.  She had started to notice that stallions were different, but only now noticed how much bigger her brother was than the rest of them.  His size was stiff, hard, pulsing against her chin.
   Shining felf the warmth of his sister's cheek as the length of his cock pulsed against the warmth of her face.  He was confused but excited as his sister looked into his eyes as penis throbbed against her mouth.  She didn't know what to do, but couldn't help but instinctively mover her mouth closer to her own brother's penis.  Her eyes closed as her lips enclosed the tip of his cock as it pressed against her face.  
   Any sense of shame Shining had was overcome by his sister warm lips enveloping the tip of his cock.  Mares had come and gone to suck his cock but this was his own flesh and blood.  Twilight moaned as the tip of his horse cock passed through her lips over the top of her tongue.  She had seen other horses naked, but none this big and full.  Twilight felt her brother's cock pulsing in her mouth as she sucked, his hand guiding her head back and forth.  She didn't know why but her hand massaged between her legs, feeling the wetness even as the hot water beat down on her and her brother.  
   Shining watched from above as his sisters head rocked rhythmically back and forth over the length of his hard penis.  He felt the familiar surge as the magnitude of his cock began to tingle.  Other mares had brought him to orgasm before but his own sister's tongue, coupled with his balls resting on her chin brought him to and edge he didn't think possible.  He couldn't imagine bursting all over his younger sister's face, but it was exactly this thought that made his cock even harder, brining him closer to the precipise.  His shame only multiplyed his excitement and he squeezed his loins in a paltry attempt to delay the inevitable explosion that was building at the tip of his cock.  
   Twilight moaned as she rubbed herself and opened her eyes to look her brother directly in his eyes.  Shining felt the pulsing in his balls vibrate from the underside of cock to the tip of his sister's tongue.  Twilight felt a surge of sweet stickyness on the back of her throat.  Her brother moaned and a burst of warm precum squirted from tip of his cock into the back of her mouth.  The stream from the shower was superfluous as her own warm juices flowed down her fingers as they pushed inside her.
   The thought of her brother naked had always made her warm and wet, but actually having him inside her mouth drove her over the edge as a torrent of her own secrections shot out as an orgasm overcame her.  Shining attempted to grip the wall of the shower walls as his baby sister moaned as her lips sucked at the end of his cock. In her excitement she bit down ever gently as his cock pressed against the back of her throat.  Shining's cock was now on fire as the slickness of his sister's mouth was only matched by the tightness of her lips around his shaft.  He knew he was beyond the point of no return as the electric pleasure flowed down the length of his cock  and began flowing over the slippery surface of his little sister's tongue.  She felt the grip on her hair tighten as a spurt of sweetness erupted into the back of her throat.   Shining moaned as several torrents of cum surged out the end of his cock into his baby sister's mouth.  The taste of her own brother's fluids brought the vibrations between her legs again as she attempted to yell as a deluge of her own fluids flowed over her fingers.  The glut of cum in her mouth muffled her sounds of enjoyment as the cream from her brother's cock flowed over her lower lip on to her adolescent breasts.
    Shining was breathing hard as the last drops of his arousal flowed down his sister's forehead down over her muzzle.  Her entire torso was covered in the results of her brother's excitement.  As she rubbed the thick result of her brother's arousal into her undeveloped breasts she looked him in the eye and said:  "Next time I expect a full service wake up call..." She eyed the still thick fullness of his cock and returned her gaze to his eyes, "Big Brother," as she smiled and exited the shower.