SHHHHRRRRRRRRRRRRRRRRRR
The showerhead rains its water down on a pair of Dobermanns, a 25-year-old man and his 4-year-old daughter.
"Up, up," Jackson says, prompting his daughter, Lily, to raise her arms. He scrubs her armpits and the sides of her torso with soap, "Good girl."
SHLL RUB PLT
As he massages the soap into his daughter's fur, though, he can't help but get a little distracted, his eyes wandering to the little one's undeveloped breasts, then lower down...
PLAT PLAT RUB
"Daddy, why is... why your peepee getting bigger..?" Snapped out of it by his daughter's words, Jackson realizes with embarrassment that his knotted cock is rock solid. Unsure how to respond, he tenses his muscles to try and kill the boner while thinking up what to tell his little girl.
Then, the little one reaches out and touches the erect member with a curious hand, and it's the final straw for Jackson's self-restraint.
"Umph-! Daddy, wha-"
PLAP PLAP PLAP
He pulls his daughter in close by the back of her head, slamming his knot into her maw and forcing her throat up and down it. Immediately, she begins to gag and push against him futilely with her little arms.
"Fuck," he whispers under his breath, too aroused to think clearly but very aware that he's certainly scarring his little girl for life. No going back now.
He pulls out of the little girl's mouth, leaving her sputtering and sobbing, panting for breath. Poor Lily is unable to even speak to call into question what just happened.
She doesn't get the chance to collect herself, though, as her father picks her up by the armpits and pushes her against the right wall of the shower. He pins her between himself and the wall and stuffs his cock deep inside of her pussy.
PLAP PLAP PLAP
Jackson keeps his hands on a rail on the wall for support, just above his daughter's head, and the little girl begins to scream and cry.
"UUUUWAAAAAAAHHHHH!!! DADDY!!!" the little one yells. Jackson is only further, more deeply aroused.
The child's reproductive organs are undeveloped and small and are thus unbelievably tight. There's no lubrication at first, which only makes it more painful for the little one, but soon crimson red blood trickles out of her and runs down Jackson's cock. It's lubrication enough for Jackson.
The red fluid drips down into the running water and is swept into the drain as Jackson slams into his daughter rougher and faster.
SLAM SLAP SLAM
Lily continues to scream as her father destroys her from the inside. A fire has been ignited inside of the older Dobermann, and her cries only serve to fuel it.
SLAM SLAM WHAM
Lily begins to choke on her own tears as she feels her delicate young uterus torn to shreds by her ravenous father's cock. Her screaming slowly dies down into retching and uncontrollable sobbing as Jackson remains relentless.
SLAM SLAM SLAM
Just as she's beginning to lose hope that the sudden abuse will ever end, she feels him slam into her one last time, thrusting his cock all the way inside of her tiny pussy, knot and all.
SCHBLRRRRTTTT
He pumps a dozen fat strings of thick, juicy cum into his 4-year-old daughter and stands in silence, huffing as he keeps her pressed against the wall, his knot expanded in her pussy.
Finally, the glow of arousal begins to subside, and Jackson looks down at the sobbing, convulsing, bleeding mess he's made of his daughter. Her blood is smeared into the fur around the base of his shaft, and her little hands cover her eyes tightly.
"Fuck, I... Huff..." Jackson puts one arm around his little girl and moves away from the wall. He sits down against the back wall of the shower out of the water and holds her tight as she sobs into his shoulder. "I'm sorry, sweetheart, Daddy didn't- he... Fuck."
His knot is still buried inside of her as she grips him as tightly as her little hands can. He runs his hand through her hair and questions what's left for him after doing something so heinous.
He can't bring her to the doctor; they'll know right away what he did to her. He doesn't know anyone underground who could treat her, either, of course. He's never done anything like this before.
Even if she heals on her own, what happens when school starts back up in the fall and she has the opportunity to tell her teachers, or heavens forbid if her mother ever decides to come see them again?
He finally comes up with a way out of the mess. It's horrible, and it turns him on even more than he had been when he first started raping her an hour ago.
"Unphf-" he grunts with effort as he pulls the still-sobbing child off of his knot. It takes some effort, and judging by the noises the little one is making, it hurts an awful lot.
SCHKLRRRK DRPLTLRLTLRTRRR
Once she's free of his cock, a mixture of her blood and his cum pours out of her. In comparison to the small size of the little one, it's a lot.
"I'm sorry sweetheart, but Daddy's going to enjoy this a lot," he whispers before grabbing one of Lily's little paws and stuffing it into the tip of his cock.
SHLLRK
The little girl is too busy sobbing and trying to process the agony she's in to much care what's happening to her now. 
Just the one leg stretches out Jackson's cock by a lot and feels heavenly to stuff inside, but when the next one is stuffed in, it's even more incredible.
SHLK SLRRRK LLG
Soon, the little girl is up to her hips in the bloated-out member, then past that. It becomes too much for her to ignore despite the pain she's already in, but there's nothing she can do.
SHLRRRK SHLLK
Jackson makes sure to stuff her arms in with her torso as she goes down, and in no time at all, only her head remains outside of him, the rest of her forced into his balls. Her teary eyes, barely held open, stare up at him, full of pain and betrayal, and he smiles back at them as he stuffs the rest of her in.
"Bye-bye, sweetheart~"
ULP
The little one begins to struggle, creating sweeping bulges that squirm their way across her father's ballooned-out scrotum. It must take a lot to fight like that with her little body so damaged already, but it's much too little much too late.
PLAP PLAP PLAP
Jackson relaxes against the back wall. The hard part is over. His daughter is inside his balls and melting. No one will ever find her. Now is the part where he can relax, relax and enjoy the sensations of the 4-year-old slowly churning away as he strokes off.
PLAP PLAP PLAP
He reclines in ecstasy for nearly a half hour in this way, beating off slowly as the heft and movement in his balls takes over his senses. Eventually, though, the movement stops, and it's about time he gets out of the shower.
He slowly gets to his feet, not taking his hand off his dick, and he leans over the shower drain.
PLAP PLAP PLAP SPLRRRFBRLBLRPRRTTT
A powerful blast of his former daughter shoots out of his cock and splatters all over the inside of the shower. The walls and curtain drip the stuff, and it forms a shallow pool on the ground that slowly filters through the drain.
"Fuck, Daddy made a mess of you, huh?" Jackson huffs as he stands on shaky legs in the lowering tide of cum.

It's another half hour before Jackson is cleaned up and out of the shower and an hour more before he's worked up the courage to make the phone call.
"Hello, I'd like to report a missing person, age four." He's pretty sure they won't find her.