Incest Seduction/Tickle Kim's butt

You don't even bother to get a word in. Better to shut her up with action!

With Kim's butt practically suspended in front of you there couldn't be a more inviting target. The moment you lay your hands on her rear you watch her cheeks clench with almost startling detail, the thin yoga shorts revealing every twitch and movement.

"EEEE! WHAAHAHAHA!"

Kim's squeals make you smile. Maybe you've missed this too.

Her body nearly spasms as you assault her small tight bum. She kicks blindly behind her, either to ward you off or kick her way off the couch, but you're having neither of that. With some difficulty, you wrap one arm just above her knees and lock her in place as best you can. She continues to kick her feet and thrash her arms but it becomes clear she's not really trying to get away from you.

"Have we found your weakest spot?" you ask.

"Yes! Yes! I caAH! HAhaha...! HAHAhahaha...!"

You run your fingers back and forth along the seam between her butt and her thighs. Her thrashes and kicks seem most genuine when you dig in there. You can't say you've ever fondled your sister's ass before, but it is a surprisingly effective tickle target. And however hard it may be to admit to yourself, you're really enjoying this. Kim's little ass is nothing short of amazing.

You can't help it. You just have to spank Kim's ass.

That's probably enough for now. Grab hold of Kim's shorts and yank her back onto the couch.