Incest Seduction/Unhook Kim's bra

You clear your throat and swallow hard while your sister bats her eyelashes innocently.

"Okay. Couldn't hurt."

"Good!" she smiles, turning back into your lap. "Then you can give me a proper rub down!"

With your sister's head and hand pressing onto your cock once more you gingerly release the tiny hook holding her bra in place. The band springs open, her cups shifting and shoulder straps loosening. You could almost swear she just giggled again.

The tight band has left a light imprint in her skin. You place your hands in the centre of her back and rub outwards and upwards, massaging the skin that had been gripped by her bra.

"Perfect. Muuuch better. Rub everything!"

With your sister's encouragement your hands explore her back. You firmly rub one shoulder, then the other, pushing each bra strap further away in the process. You run your thumbs up either side of her spine, then downward to the top edge of her yoga shorts.

Your fingers slide up her sides, one being easier than the other since she's still not laying on her stomach. But at least the one side is still very open. So open in fact that your fingers push the band of her bra away completely. You're not even sure you did that accidentally, but you've managed to push her bra away from her body, the shoulder strap slipping most of the way down her arm.

Now it's not only her back that is fully exposed but her boobs as well, although you you can't see much. One is teasingly visible to you with your fingers mere inches away. You pause the massage, wanting to stop yourself to at least think. And just as before, you think you can hear - or perhaps feel - light giggling coming from your little sister.

What now?

She doesn't need her bra for a back rub. It's fine.

You're not going to be able to control your dick anymore. Better at least get her off your lap.