Manufactured Misfortune/Day1-Anatomy-Med/Peep on Emily
You just have to see what she's doing. Carefully turning the handle and inching the door, you open just far enough to spot Emily in her bed. Your sister has her eyes closed, but she's not sleeping. A thin sheet is pulled over her haphazardly, the rest of her bedding pushed to the side, with only one arm visible above her head. But it is not difficult to tell that her other arm is running down the front of her body since her hand is twirling under the sheet. Her legs are splayed open, knees to either side, with her ankles meeting again at the bottom of the sheet. One row of toes are poking out from beneath the thin covering.
Emily lets out the occasional heavy sigh as her hand alternates between frantic shaking and gentle circles at the top of her open legs. Her head lists from side to side and, rarely, a soft moan escapes her. You paw at your own dick through your pants and have half a mind to just whip it out and jerk off right along with her. But that isn't really an option. As it is you've already been standing in the hall for far too long creeping on your sister. You don't want Emily to catch you watching her, but you don't want your parents to catch you either.
You almost walk away but this is too good an opportunity to get your sister really embarrassed. You draw a deep breath then throw her door open.
"Hey sis."
"Ahh-hah!" she gasps, a mix of pleasure and shock. "Ron!" Her legs quickly close and her eyes dart for only a moment before she sits up and hurls her own pillow across the room at you. You catch it with a chuckle.
"Well I love you too," you quip, walking her projectile back to her.
"It's bed time!" she announces in a hushed shout, swiping her pillow from your outstretched hand. "Go away!"
"I just wanted to talk for a sec." You take a seat on your sister's mattress beside her feet. While your sister is cautiously replacing her pillow behind her, you notice that both of her feet are now exposed. Between her legs slamming shut and her violent throw, her has sheet shifted. But that part isn't really what caught your eye; it's the sight of her panties wrapped around her feet, below her ankles and past her heels.
It takes all of two fingers for you to pull them past her toes. She tries to pull her feet in once she realizes what you have a hold of but it's too late. You lift her rolled and twisted panties into the air, hanging them off of one finger. "Actually, I was going to remind you about your dare tomorrow, but I can see you're already practicing."
She swipes her panties away from you, but far more sheepishly than her pillow. In fact she's blushing so much that her cheeks are nearly red, even if they were quite rosy to start with. She looks torn, like she's unsure whether to toss them aside, put them back on, or throw this too at your face. So instead she just sits there holding her underwear in her hands, both of you very aware that she's bottomless beneath her airy sheet.
"I'm not practicing. I.. didn't forget though."
You simply nod. "Yeah. I've been thinking about the dares we did today too. And about all those losses you had."
"Shuddup!" she boops your side with her foot. "Some of those dares were really hard!"
"Yeah, they were!" You drop a hand onto the top of one of Emily's knees, playfully pushing her bent legs from side to side. She keeps them tightly closed. "But I guess I've been thinking more along the lines of you... being my slave. You know what that means, right?"
"Yeah. I just do whatever you tell me to."
"Sure. But that could be anything."
"Yeah."
"Like... anything." You lower your hand and lock your fingers around Em's exposed ankle. You give it a tug and she lets you pull her foot onto your lap, part of her bare leg now sticking out from under her sheet. Her heel rests atop your cock as you rub her toes.
"Yeah..." she repeats, gazing nervously at her foot.
"I could be ruthless. Anything means... a lot of things. Way harder than just a dare."
She stares intently as you tweak her toes and rub her arch, transfixed by whatever it is you're about to do to her foot. But you don't really do anything. You just let her mull it over. She then locks eyes with you and says, with a smug look, "You're not gonna scare me into chickening out. I told you I'm not a cheater."
You grin. "I guess we'll see."
Gripping Em's ankle firmly, you tickle the underside of her foot. Em squeals and lashes out with her other foot, kicking wildly. Her sheet waves in the air giving you glimpses of the bare slender legs bucking you from beneath. Once she kicks you enough that it starts to hurt, you let go of her and stand from her bed.
"Yeah, you are the cheater, remember!" she says pointedly, catching her breath.
"Well tomorrow I won't be. Anything I say goes. I could tickle you for hours if I wanted to, 5 hours if I remember right."
Em starts to smile, then bites her lip trying to hold it down. She can't keep your gaze any longer and glances down to her disheveled sheets, shifting her legs to push them about and give her something to do.
Dad peeks in from the hallway telling you to leave your sister alone and go to bed. That spooks you both, at least a little, and you are quick to say goodnight and leave Em be. But once you're standing in the hallway by yourself your dick reminds you of how horny you are.