Sister, lust filled stupor

The box of your sisters adult gear had been pulled out from beneath your bed and opened, numerous toys lay scattered around your ground as she seemed to have dug many of them out in a frantic pace. The book, unopened it seemed to your relief, lay on the ground next to the box, seemingly ignored in your sisters haste to have at the toys.

As for your sister. You could only stare at her formed draped over your bed belly down. You could hear the constant thrumb of the vibrator she was pushing in and out of herself with her fingers, while her ass hung off the edge as she desperately tried to pleasure herself. She wore a buttoned white tee, though each button had been opened or ripped, as her other hand eagerly groped her breasts. She wore nothing below the waist.

“Oh my, all that wonderful energy.” The succubus started, “Your sister is a magnificent lust battery.”

It was hard to process in your shocked mind, but you could sort of tell what she meant. It felt like some sort of thunderstorm was going off in your room, a heavy sort of pressure pushing out from your sister, that seemed to threaten to wash over you. Yet your body felt pulled in, as though you were thirsty in the desert and saw a cool glass of water.

Then your body did begin to move, and for a moment you thought you were indeed being pulled in, but instead to your sister, it stepped toward the book. The succubus using you to pick it up and check it.

“Hm, some residual magic but I doubt she did more than glance at a few pages.” she commented before putting the book on top of your dresser, “Well then, I guess we should check more intimately on her. I can't believe how well she reacted to my earlier charms!”

As another step was taken toward her, she suddenly seemed to realize she was not alone as she twisted her body to look at you, her hands stopping from her self-pleasure and started to push herself off her bed. The succubus did another finger movement towards her as she raised her self up, a few words that you were not quite able to catch accompanying the movement.

“Who are you?”

It took you a moment to realize that she did not recognize you under the whole latex schoolgirl thing. That whatever prevented people from realizing who you were tonight at the party was still in effect.

“Oooh, this could be fun darling, I'll run with whatever you tell her!”

You could tell her it's you, try to explain everything that is happening. She might be able to help. Or... You could pretend to be your own girlfriend or something, try to protect whatever remained of your dignity. Heck, you could just stay quiet and let the succubus decide what to do.