Jacob blushed as his fingers brushed against the soft fabric, the pink cotton sliding between his fingers. He bit his lip as he looked around, eyes darting across the pink of his sister's room before finally settling on the filched panties. He hesitated for a moment before clutching them to his chest, balling the smooth cloth in his hands before darting to the room next door and collapsing on his bed.
He sighed in relief, happy to have succeeded cleanly this time as he glanced furtively around the room, eyes resting on the closed door for a moment before his gaze relaxed. He smiled to himself, as he hooked a finger to each side of the jeans and began to tug. The cold air sent shivers down his spine and down into his brain as the cloth slid smoothly down his legs, the hair shaved clean beneath its covering. The underwear slid off next, flopping to the floor.
He lifted a foot from the pile, leaning back a little as he carefully placed one foot then the other through the cotton holes, pulling the band up around his waist as the blush rose up his face. The cloth stretched against his skin, biting in a little as he squirmed. It restricted, too suddenly to move and too quickly to cry out as it pressed down on his manhood. He didn't dare to scream, every opening of his mouth leading to pain sharp enough to gag on as it dug further into his being.
He watched instead, staring as he watched the tightness ripple across his legs. He watched as they pressed inward, slenderizing across his body as the already clear skin turned downright silky. He kept his lips shut firmly as he wiggled his toes, rasing a hand to his mouth at the sight of their petite form as the changes began to crawl back up.
Pleasure washed through his body as the force regathered in the panties, tightening anew around his manhood for a moment before letting it travel like a flood across his body. He gasped in shock at the chill of it across his stomach, flattening his body before splitting on his chest. His arms stood still, pinned against the bed as his shirt tightened down around him, the arms slenderizing to match as the sleeves began to disappear. He didn't even put up a token struggle as it bulged outwards, pleasure blossoming through his body as two spheres of flesh pressed themselves outward. Pain tingled through them, the sensitive nipples rubbing against the fabric, hardening as the cloth began to soften. He shuddered a little as he felt cold buttons appear against his flesh, his face burning as it reconstructed itself. A giggle tore its way free from his now petite mouth, hair growing outward as he lifted a tiny little finger to his own lips in wonder.
He felt them pulse beneath his fingertip, plushing out a little before he traced the rest of his face. He felt the nose turn petite, the face shift as he looked at the mirror, already certain of what he'd find. An eighteen year old version of his sister.
He turned his face away from it as the panties tightened again, thinning out as the cloth rippled forth from the edge. He squirmed a little more as it pressed into his manhood, folds of fabric falling outward even he felt a part of him slide inside. The pink skirt fell against his knees as the bulge in them disappeared, manhood sliding inside forever as the new girl blushed.
It deepened as she glanced up, his gaze drawn to the creaking door as a figure slipped inside. Se tried to back away, pausing when she saw a face that mirrored her own. "Sis?" she squeaked, eyes bulging a little as she saw the formerly fifteen year old girl now a twin.
"So, I found this awesome book of spells," grinned Lita, "for people who wanna make a little change in their life? Thought you and my pink panties could use it."
"You... you knew?" squeaked Cobi, swallowing a little at the look her sister gave in a return.
"You talk in your sleep, sis," she grinned. "Now, come on! You sooooo owe me a night of being a wing girl."