You get pushed into her urethra.

Original Author: Nightmare Pony

It is immediately after one of the blasts of seed that your head slaps into your sister's urethra. Kim gasps at the sudden intrusion in her massive girl cock, and screws her eyes tight in pleasure, not noticing you. Meanwhile, you have your own eyes shut along with your mouth, and you're holding your breath so as not to drown in your older sister's spunk.

Your head does not quite seal the hole, and girl sperm continues to rush past you, spraying out around your head and trying to push you back out. Unfortunately, the monster between your sister's legs has too good ahold on you for you to be pushed out, and your current state does not last long. With a few more twitches of Kim's member, your neck and shoulders slide in, completely blocking the flow of sperm.

Kim moans loudly, as she feels the pressure building and the wonderful thing sliding deeper into her, whatever it is. It feels FANTASTIC, and her legs start convulsing from the pleasure. Yet she needs relief. So she quickly presses her finger against whatever has found its way into her girlcock, and shoves it the rest of the way in.

You're shocked when you feel something press against your butt, and push your entire torso in. When the same thing touches your feet you realize your own sister is feeding you to her dick. You briefly wonder if she knows it's you, and is she possibly punishing you for being a pervert? You don't know, and as she pushes the rest of your body in you stop thinking about it. Because then your entire world begins to shake.

Kim can't stop groaning, hissing, or screaming in pleasure. She'd never imagined ANYTHING could feel this good! Yet it's also **** not being to release, so she does the only thing she can think of. The geeky girl wraps both her hands around her thick beast of a cock, and resumes jerking off. She's rewarded by the intrusion mercifully sliding deeper into her.

The persistent slap of your older sister beating herself off reaches even into the muffled, hot, tight, and cacophonous environment you find yourself stuck in, and much to your horror this speeds up your sinking. It isn't long before you fall into a surprisingly roomy, yet still confining, chamber filled with an unmistakable thick liquid. You're now in your older sister's right testicle. The concept is almost mind breaking. Immediately a scream louder than the one from Kim's initial orgasm rocks your prison, and her balls empty in a flash. Leaving you trapped in an teste.

Kim lay panting on the couch. Once whatever was in her manhood fell into her sack all the cum she had had erupted in one continual stream. She didn't know what had happened, but she was glad it did. Lethargically, she stroked her right ball out of some odd form of gratitude for what she could feel was now trapped in there.