"Agh! What the fuck?" you were startled awake and surprised at the sight of your billionaire father holding some sort of device ominously over your naked body.
"Good morning Ted. Say hello to the Chronivac 4.0. It's my latest rich boy toy. It's not just a computer or a 3D scanner, it's an experimental reality-subfield modulator. It can change anything about my life that I want it to, or anything about yours."
"What kinda shady-ass pyramid-scheme bullshit is--whoa..."
Your dick is growing. At first you think you're just getting an erection, which is embarrassing enough in front of your dad, but by the time it's thicker and longer than any erection you've ever had, it's still soft and floppy enough to dangle limply on the bed. It soon starts pointing up a bit higher, though, not because its stiffening any, but because new dark skin growing around your member and attaching against your belly. Soon you can't even see your dick anymore because of this strange covering. Fortunately, it doesn't take too many seconds for your curiosity to be satisfied. While you're still scratching your head awkwardly at the sight of this strange pouch on your abdomen, a weird hose-like organ starts worming out of it. At first it's thick, wrinkly, and not much longer than its sheath, but it keeps growing. It practically unfurls from within you to dangle between your legs, well over a foot long. It's jet black except for some patches of pink on the more distant half of it.
It's disgusting, but partially to your surprise, it starts pounding erect. Pulses of blood start pumping into it, inflating near the base and then eventually making the whole thing stand stiff in front of you. The tip, which was flat but slightly pointed, swells up and out into an unsettling trumpet-like shape. Out of curiosity, you reach out and grab the thing about two thirds of the way up. An exciting tingle runs down the shaft, then from your head to your feet. You realize you'd like to pleasure this pillar a little more, but you snap out of it and look back up at your dad.
"You gave me an enormous cock?" you say with a mix of amazement and criticism.
"Well, it had to be pretty big for what I'm gonna use it for," he said slyly.
"What, is this one of your fag fantasies, old man? Fuck if I care what you do with your prissy boy-toys on the other side of the mansion, but don't think I won't tell mom about your little incest machine. Even if I am grown up, it's fucking sick--"
"Oh, please!" Dad interrupts. "You really couldn't think I'd wanna do THAT with YOUR cock! Heck, most humans probably wouldn't know what do with it! You don't even know what kind of penis that is now, do you?"
"All I know is--um--uh--wait, hold that thought, pervo, I gotta go handle something..."
You may be pissed, humiliated, grossed out, and ready for your real dick back, but you're also hornier than you are able to withstand. You just can't think straight with this inhumanly large boner throbbing in front of you. It's either prance to the bathroom, or jack yourself off right here in front of your own father, which the messed up psycho seems to want! Fortunately here in your dad's mansion, you have a private bathroom that opens right into your bedroom (and a similar setup in all the other bedrooms your have to choose from). You sit down on the toilet, grip the giant shaft with both hands, and start taking care of business. You're impressed by how good it feels, in spite of how ugly it is! Your hands brush up against a weird wrinkle of skin around the middle, and you can't hold back the moan that echoes around you. Now that you've found this monster's weak point, you can't get enough of teasing it! Barely a minute has passed before your groin muscles are holding back an ocean. Your trumpet-flare swells out to its widest and roundest shape yet, just before the tight, wet pressure in your crotch surges up through your lengthy shaft. A blast of white ooze flies up into the air, then another, then another! When it's over, your bathroom floor is soaked with sticky, chunky, off-white paste that is apparently what your semen looks like now. Your dick has slumped over again, hanging loosely over balls that are way larger than the ones you woke up with, and you're panting for breath. You throw some towels down and splash some water in your face before opening the door and going back out to your father.
"Well, I must say old man, that new toy you gave me isn't so bad to play with. Sure makes one helluva mess, though!"
"Well I'm glad your having fun with it, because you do get to keep it. You see, one of the many small farms I own is about to become a small but unnecessary liability if they can't replace their brand new quarter horse stallion that died unexpectedly last week. The more 'messes' you make with that new 'toy' of yours, the better off we'll all be."
"What are you blabbering about, moneybags?"
"Didn't you notice the tail yet? Or the ears?"
Come to think of it, you did notice some odd twitching feelings in both your ears and somewhere else, but you were too "preoccupied" to notice. You were sure you even felt yourself slapping the toilet with something during your orgasm, but ... come on, I mean, that orgasm!
You reach up to your ears and are surprised that they aren't actually where you expect them to be. They're higher up on your head, and they are too long and pointy to be your own. And worse, they really are twitching around in your grasp. Remembering what your dad just said about a tail, you turn your head quickly to look down your back. Sure enough, there's a long curtain of sleek, brown hairs hanging from your bottom and dangling almost to the floor. It looks exactly like a horse's tail. It flicks around when you try to move it.
"You're turning me into a HORSE?!"
"A very PROFITABLE horse!"