Turn and face her

You do a complete 180 and you sister almost bumps into you.

"I didn't expect you to actually face me" she says mockingly "I would have thought you'd learn by now that you never win"

Hearing this makes you quite mad and you send a telegraphed kick towards her crotch.

Unfortunately she saw it coming and caught your leg right before it hit its target

"Too slow" she says "As always"

She slams her knee directly into your gonads and you can feel and even hear them squish against your pubic bone.

You try your best to keep conscious, but her knee keeps pressing your nuts further and further up