Sally & Emily's Bedtime #2 (Commission) (Pixiv Fanbox)

Emily quietly plodded back down the carpeted hallway, her bare feet trying to stay quiet as to not wake her little sister.  She knew Sally was a light sleeper. But...as she passed by Sally's door...she heard the soft whirr of her sister's laptop cooling fan...followed by a faint moan...and a whimper.  Emily's brow furrowed.  Their mommy had told them to go to bed over an hour ago.  Neither of them should still be awake.  But the noises piqued Emily's curiosity...and she silently swung open Sally's door.  

She couldn't believe what she saw.  Her innocent little sister, fingers deep inside her pussy in the throes of masturbation, her eyes rolling to the back of her head as she rushed through the throes of another orgasm.  Emily's eyes widened.  She'd heard about masturbation from the other kids at school, but she'd never seen someone else do it...let alone her virginal little sister.  The big sister's pussy immediately moistened.  Just watching her sister pleasure herself made Emily dizzy with lust...