"We'll need to take some 'samples'." the gremlin said with a grin. "Purely for scientific witchery purposes, I assure you."
The short fat gremlin slid aside some chairs and leisurely walked out from behind the desk, unhooking some suspenders and showing off a nametag revealing him as 'Mr. Gremian'.
"This won't hurt, but it will be unnecessarily embarrassing and potentially uncomfortable." Mr. Gremian said with a sigh. "Did you know fresh gremlin semen is a natural counter to goblins' favored magic types? It's a bitch with talismans, sometimes it's like pouring water on electronics. Course, that means I'll need to get behind these shields. Relax and give in to whatever the magic's prodding you with."
Without any overt physical motion, faintly glowing white symbols slid out on a slithering silver-trimmed bluish pathway, forming a cagelike array on the ground around Willy. Willy fell to his knees and started thrusting uncontrollably atop the magic circle.
"What's happening?" he asked, overcome with lust.
"My diagnostics." Mr. Gremian said flatly, casting a mildly disinterested glare at the human's twitching micropenis as if the shield around it was supposed to be some coat rejected by nudity. "They're not as elegant as the headmaster's but I check thoroughly for some stuff he'd brush over. And uh...I jack into biofeedback for this part. Works as a backdoor lust spell and domain assertion, magic endocrinology bullshit. Wow, your penis really IS that small? I thought it'd be the spell compelling you to say stupid stuff or something but I'm not seeing that in your genetics or spirit field."
Willy felt gazed upon by some invisible crowd, and as if he was being gently touched by lots of invisible hands. Mr. Gremian slid off his own clothes and walked into the circle proper, the trail of silver contracting after him and adding slowly rotating rings around the spell area.
"Um...right, gremlin cum." he said with a stereotypical 'heh-heh' and something that resembled the slightest bit of abashment, scratching behind his head and gently rubbing three and a half inches of soft gremlin cock, which coupled with girth dwarfed Willy's cocklet as he pressed up for comparison, standing about as tall as Willy was kneeling. "Tastes like mayonnaise and the need to call tech support. See, uh...you're in need of a job after that scholarship, right? You're cute enough, we could make this a regular arrangement or something. I pump a load in you whenever I want and drag out a charge of that curse through Mr. Headmaster's curse collector shield, I pay your tuition and handle, uh...the necessary spellcasting to keep your next few years of nudism below question. And I do mean any time, in the middle of class, while you're sleeping, for your lunch, whenever I feel randy at all. You good with that?"
"D-do it to, to me." Willy stammered out, frotting his insensate junk against the gremlin and getting more out of it from his legs. "Anything y-you want, whenever you w-want."
"Alright, alright." Mr. Gremian acknowledged the very manipualted agreement, gently pressing Willy's head down toward the hardening gremlinhood's slightly-over-five inches. "Suck it, and don't bite too hard. We can work on your technique, I'm still analyzing your problem. Looks like a bog standard nudity curse at first blush, just a pretty high charge, there's the spread suppressors Headmaster's got on it, huh...perception filter to amplify embarrassing situation other people reacting stuff, we'll have to keep track of that on the luck flows if Headmaster failed to pick up on it after being hit two or three times. Pretty deep down, but the coat's definitely full-penetration so that's to be expected. Stuff's squirmy under there, but I have authorizations for school standard stuff so I won't need to crack the shield to do more than look."
With a gentle tug on Willy's head as he thrust in, Mr. Gremian raised a hand and let an arcane sigil form before letting it join the other in blowjob guidance, signaling the protective bubbles to stand down to whatever he wanted to do with both them and the curse inside. Unrelatedly, it gave him a lot of latitude with Willy, not that he wasn't already exploiting that as 12+1 manager. Well, all's fine in his head, he's effectively giving the man a full ride scholarship and a sugar daddy besides. Speaking of full rides....
"Ah, shouldn't react to a force clean lube." he commented while pulling out of Willy's mouth. "Speaking of authorization, I'm authorizing myself into your asshole, back up and bend over."
Giving Willy a light and unnecessary slap on the ass, the gremlin cast a convenience spell on his dick and let the sudden chill of lubrication and relaxation finish taking Willy's virginity as he worked his way in and started really breeding. Leaning forward and reaching up to play with Willy's nipples, it wasn't long until Mr. Gremian came excessively, a thick creampie from just one load.
A small squirt of contained energy bubbled out from the shield around Willy's sealed genitalia along with some semen, before teleporting into a warded glass jar inside a nearby oblong anti-tipover cabinet table.
"One week off, lots of weeks to go." Mr. Gremian joked accurately, letting himself pull out of Willy and haul up the young man. "Alright, maintenance casting..."
With a fingersnap, Willy felt the thick gremlin cum inside him mostly dissipate into magical effects and suffuse the barriers around him, vaguely resembling flavorful bukkake before fading from noticeability.
"Now, follow me for a bit, I'm still diagnosing." Mr. Gremian said, seemingly having lost interest as he bothered to cast some minor cleansing on himself before stepping away (sending the spell trail into extended mode again like some form of videogame highlight). Sliding back on his clothes without any dramatic stripping explosions as Willy got up and aimlessly stood behind him, he glanced at the jar and added "Looks like that embarrassment component is a delayed trickoff, it's..."
Willy quivered and thrusted a bit, but no cursed cum came out...locally.
"Oh for fuck's sake." Mr. Gremian said as alarm bells and scrolling panels of magical script formed around him. "Found the blasted trick. It's not a cheap cockshrink, it spreads based on embarrassing unlucky stuff happening and tries to coerce it. And it's probably escaped containment, bleeding a bunch of charges off elsewhere through an anti-field sharing oversoul. Lucky as all hell half the class is apathetic sociopaths or we'd be a nudist colony by now, but it looks like we'll need to drop decency guidelines for a week. While we're at it, we'll need to make everyone either way nicer to you or way hornier or that triple seven is gonna be over in seven. Less if people are such idiots the test case burns out the battery. Still, I think we've got the curse's reaction potentials pretty understood, I'll file an injunction so nobody forces you to cast or be cast by something that'd affect it immitigably, we'll get the other curse victims corralled, and..."
The gremlin facepalmed as the barriers around Willy gently glowed various colors for autonomous spell-tagging alerts, before he groped Willy on the willy to confirm sensation had returned a bit. "I'll wire you into the nega-scandal perception filter to tag the curse. Pretty insidious but otherwise a pretty understood thing to counter, we'll just change the cage to filter out other people's shame responses and staple on a replacement implication so the curse can't spread except by it being fucked out of you. And I've stuffed your internal spell field with enough gremlin cum to keep that puny little wiener on tap for discharge, with refills as soon as I'm horny again."
Shuffling through the parchment on his desk as the silver diagnostic runes darkened to a perception-weirding shift of opposed color, Mr. Gremian offered Willy a bunch of options to repaint this curse.
"I could do all sorts of things here, but for once today I value your input on the matter." he said, with a light flick clearing Willy's head of particularly objecting to the rush of seduction and control he'd just been subjected to. "Look over these and tell me what strikes your fancy, we could change it later. Go on."
Finally finding his voice after the haze of lust lightened, Willy decided he would replace environmental embarrassing luck with...