Incest Seduction/Massage Kim's calves
From Create Your Own Story
You smoothly transition to your sister's calf muscle after finishing up with her feet. You poke the meatiest part trying to get a feel for how to go about this. You're still making this up as you go. But that feels wrong. You settle on long even strokes along her calf instead, figuring that's probably the best option. Kim coos in agreement nestling her head into her arms.
Obviously Kim's thighs are next. You continue the same technique as her calves, with smooth long strokes going up the length of her leg. The realization that your youngest sister is still quite tiny dawns on you as your fingers can almost wrap around the back half of her thighs, which are milky white and lusciously soft.
With every stroke your hands move higher and higher up your sister's legs. The towel draped over her covers a small portion of her upper thighs. It would take little effort to simply massage underneath it, but you're not sure what a "proper" masseuse would do in this sort of situation.
Fold Kim's towel up onto her butt. You need room to work, after all.
Before you do something you can't take back, perhaps you should ask her what she would like.