No. Just tell her the truth.

Looking into your sister's demanding eyes, you ask yourself how she'd react to the truth. Not knowing what's happening is driving her nuts, but her question sounded nore inquisitive than accusative.

Coming up with excuses was never your strong suit anyway, you decide. "Sit down, I've got something big to tell you."

Sarah sits on your bed and looks at you expectantly. "This ought to be good."

Sitting down next to her, you summon your courage and make sure your emergency stamp is still in your pocket in case this goes wrong. Before you can reconsider, you reach around Sarah's back and jam your hand down her pants. "This pussy is mine because I made it mine," you tell her while pressing on it firmly through her underwear, one of the silk panties you picked out for her at Agent Provocateur. "I didn't just happen to find those words while I was drawing on you, I wrote them."

Sarah stares at you in shock. "You took part of my body by writing that you own it on me? Did you do the same thing for everything else that belongs to you now? Wait, you stole my room!?"

You're surprised that's what she's hung up on, but you suppose it makes sense. Having her room taken away was her first exposure to your mysterious power, and the way you made her doubt her own memories must have been distressing. "Yeah. Sorry about that by the way, I was still learning how this thing works."

"And how does it work? Tell me everything, Ryan."

You stroke her pussy through a layer of silk as you begin talking. You start at the beginning and don't leave anything out. Sarah listens without speaking until you get to the first time you made Kelly touch your cock with parts of her body you hadn't claimed, at which point she starts asking a lot of questions to make sure she gets every sordid detail. You don't have to be a genius to figure out she's interested in more than the mechanics of your abilities, especially since you can feel how much wetter her panties are all of a sudden. You give your sister what she wants and slip your hand into her panties as you keep telling your story, with a focus on the erotic this time.

Sarah doesn't object when your other hand lands on her leg. Her jean shorts allow you to stroke her skin almost all the way up her thigh, which grows goosebumps under your touch. When you start talking about your mom she grows quiet, except for the soft moans she can't suppress. Eventually she asks, "So it was an accident, but you did want her to touch your dick?"

"You don't believe me?" Your hand stops moving in her panties.

Instead of answering she says, "Do you want me to touch it too?"

You swallow hard. "What?"

Suddenly her hand is on the tent in your pants. "You're nice enough to make me cum. Maybe I can return the favor..."

Your mouth is too dry to respond, but your sister doesn't mind. With her eyes forward so you can't see her expression, she undoes your button and fishes your cock out of your pants. A second later her soft hand is wrapped around it. "So what happened next? Keep talking, Ryan."

Her hand moves slowly up and down your shaft as you nervously resume your story. When you tell her how your mom started asking questions about her and how you shut her up, she laughs and the tension is broken. Your start stroking Sarah's pussy again as you describe how your mom sucked your cock, the very cock she's jacking off right now. "Oh fuck," she moans and her hand wanders under her shirt to play with herself.

Sarah's moans get louder and louder as you continue your tale, and when you casually explain how you gave Kelly and her husband permission to give each other head she pulls her hand out of her shirt to clutch at your arm as her climax hits. But she never stops moving her hand on your cock, and she stays aware enough to bend it to the side so your semen shoots onto the bedsheet instead of your shirt when you cum.

The room is quiet for a while after you remove your hand from Sarah's pants and let it join the other one on her thighs. Her hand stays on your cock until she can feel it soften in her gentle embrace. Then she speaks up.

"How much of this does mom know? She said lunch should be ready about now, so we better get our stories straight before we go down there."