Fucked as a pussy

There are many strange psychological implications to your situation.
Thankfully, all of them are lost on you. All you know is, you need that thing inside you right now. You try to stretch towards it, to throw yourself onto it.
But of course, it has no effect.
Karyn steps onto the bench. You can see her submerged knees, the ripling surface of the water below you.
Her legs bend as she lowers into a squat. Your faint reflection shakes on the surface of the water.
And then you're under again. The building-sized spire is looming closer, taking up more and more of your vision. The giant mushroom head of your own dick, recreated perfectly in granite, is rising to meet you.
Your clit is rock hard, jabbing out of it's hood. Your insides are as roomy and wet as you've ever felt them, cervix pulled far back, ready to take this thing in as far as possible. Each beat of Karyn's rapid pulse shakes you just a little.
It's so close now, what must be just an inch away, and your descent stops. You want to scream.
"Jon?" You hear through Karyn's body. "I just want to make sure, this is still okay right?"
You clench once, hard. So hard it kind of hurts.
"Oh! Alright, just making sure."
It's kind of nice knowing that Karyn cares enough to ask how you're handling things, even though you're just a part of her body. Although, right now, you're dying for her to get to the point.
Your wish is granted immediately. Karyn closes the final bit of distance, and you feel your own tip slide into you. She moves her hips forward and backward, dragging the smooth stone across you. Whenever it hits your clit, a surge of excitement runs through you.
This is the real deal. You're a pussy, about to do what pussies were designed for: getting fucked.
With a final motion, Karyn lines up the tip against your opening again. It presses into you just slightly, barely opening you up.
She lowers her squat in one fluid motion. Warm stone rushes to fill you and you squeeze it eagerly, getting pushed open by the force of Karyn's weight on top of you. The veins and ridges of the stone penis rub wonderfully against your sensitive inside, a mixture of lubricant and water helping it along.
Your outside is pressed flat against the stone bench, Karyn grinding her clit into it. You're overwhelmed by pleasure coming from every direction.
Then Karyn rises up, and your desperate gripping makes you feel each vein getting pulled out in reverse. Once the thing is almost fully out, she reverses, slamming it back home, pushing your increasingly sensitive clit up against the bench again.
Then she rises, and falls again. Over, and over, and over. You're not thinking coherently, filled with the sheer pleasure of being a sex organ in use.
With the shown Karyn put on earlier, it's no surprise that you're brought right to the edge almost immediately. Karyn's ragged breathing and moaning is audible all around you, through her body.
She drops herself down onto your penis one final time. As it rushes to fill you up, and your unbearably sensitive clit is pressed against the hard stone, you come. Karyn yells as a wave of pleasure overwhelms your being, and you convulse rhythmically.