John Doe, sophomore at mage college (M)

You awake very slowly, fading in & out of consciousness for several minutes before finally you realize you're staring at an old, cobwebbed stonework ceiling. Early morning light shines through the high windows and casts bright rectangles across it.

You sit up and feel your head buzz. It takes you a few seconds to recognize the place: it's the basement of your dorm building, the traditional place for students of demonology to practice. Of course, you're the first student of demonology the college has had in years, so the place is pretty musty. It takes you a few more seconds to remember what you had been doing the previous night, even though it seems painfully obvious once you realize it: you were practicing. You have no recollection of how you ended up asleep and buck naked on the floor, though.

As if to answer your question, you feel a powerful, unfamiliar throb in your nether regions, causing you to look down at your penis. Except it's not your penis at all. For one, it's much larger than yours had ever been; easily double, maybe even triple the size. Lying flaccid on your belly, it reaches past your navel. It's also shaped completely differently, though you can't really think of anything specific about it other than its size that stands out. It just looks more virile, more brutal, than yours had ever been.

As if it knows it has your attention, your strange new penis starts pulsing and hardening, growing to a truly monstrous size; you had to guess it was a few centimeters bigger than your forearm, with a head the size of your fist. It's covered with thick veins that pulse hypnotically. You can feel the sensations of arousal, but they feel alien, mixing with your own dread into an immobilizing cocktail. You also notice an unfamiliar tightness in your balls, and you realize they've grown to such inhuman proportions that they're actually pushing your thighs apart.

Your cock is now rock hard and pointing directly at the ceiling. Little drops of pre dribble down its length, and as you look at this strange invader you feel a presence in it, a mind.

"W-what are you?" You manage to stammer out at it.

You don't get an answer, but it's very very horny. It wants to fuck. Don't you want to fuck? You realize it's probably some kind of lust demon; you'd been really drunk the night prior and had decided it would be fun to try the one thing that nearly every mage in training tries to do at least once: make your dick bigger. But for a demonologist, that was an extremely risky proposition.

"I don't know what kind of deal I made with you... can you remind me of the terms?" Disclosure of terms is a requirement in most demonic contracts, and you hope you weren't such a sucker that you agreed to one without that stipulation.

The cock doesn't seem to understand the question. It's really horny. It can make you feel good, if you let it. Without warning, you experience a blindingly powerful orgasm; jism rockets out of your cock, splattering all over the ceiling and the wall behind you.

You squirm on the ground, wracked by the most intense orgasm of you life, for nearly two whole minutes before you manage to squeak out, "Enough! Please stop, I get it."

Your cock subsides, although it's still rock hard, and you get the feeling it could go on for much much longer if it wanted to. The ceiling and walls are absolutely covered with cum, caught in the thick cobwebs and in the cracks between the stones. It'll be an absolute bitch to clean that out, you think. But the cum disappears in an instant while you're blinking.

You look back down at the achingly hard penis attached to your crotch. Okay, so it seems that you didn't really make a deal with a proper demon, you had just let a lower, animal-like demon into your body. That has advantages and disadvantages; these types of demon aren't very bright and don't tend to fully possess people, but they are also harder to predict. Still, letting one into your body was a really dumb move and at the very least it was going to ruin your week, possibly your life. You quickly check if you'd drawn any arcane symbols on your body that would make exorcism easier... nope. You're stuck with this thing until you can get a pro to help you out.

"Well... I guess I'm stuck with you for a bit." You feel a swell of pleasure emanate from your cock, like you're almost going to cum again, but you quickly say "Hey! Hey, no, save that for the ladies. I need you to go soft so I can put some clothes on."

It doesn't understand why you'd want to have clothes on, but it does like that you want to use it on ladies. It starts to soften slowly while you get up and look for your clothes.

It becomes very clear right away that even with your new cock flaccid, it's going to be a real struggle fitting it into your clothes. After much finagling you finally managed to get the huge softball-sized nuts and the big sausage of meat stuffed into your pants, and after quickly cleaning up the evidence of your drunken night you head back to your dorm for a shower.