She does

“I will go first!!” Your sister says stealing the words right out of your mouth.

You spread your legs awaiting her strike.

This time tho your sister decides to punch them instead. Probably because your last kick hurt her crotch too much.

She does a perfect split her face leveled with your crotch her pussy completely exposed.

She sends a flurry of punches to your balls from all directions. You resist the urge to puke and take a moment to regain your composure.