Good Boy warning - this contains incest, dont like dont read -----------------------------------------------------
The sun broke jagged through the grounds of the Care of Magical Creatures enclosure like it had something to prove. The dew hadn’t even finished drying on the pumpkin patches when Professor Kettleburn came limping out to greet the mixed year Gryffindor and Slytherin class, his left sleeve conspicuously flapping empty where a limb used to be.
“Right!” Kettleburn shouted, clapping once and then regretting it with a wince. “Today’s lesson! Unorthodox, yes, but inspired! You’re all going to show off your pets!”
The class collectively blinked at him.
“Your companions! Your familiars! Your beloved beasts! Something that reflects your character!” he elaborated, beaming.
"Is this a graded assignment?" Lily asked warily, notebook half out.
"Not officially. Just a practical exercise. Community bonding! Empathy! Enthusiasm for the animal kingdom!"
"Sounds fake but okay," Mary muttered under her breath, already bored.
“Some of us don’t have pets, you mad bastard,” Barty Crouch Jr. drawled, arms folded and eyes half-lidded. He leaned against a fence post with a vague air of someone contemplating whether he could murder a professor and get away with it.
“You should! Every young witch and wizard benefits from the responsibilities of caring for another living creature!” Kettleburn declared, undeterred. “If you don’t have one, partner with a friend! Share custody!”
“Like divorced parents?” James quipped.
“Like responsible young adults,” Kettleburn countered, and gave James a pointed look. “So! Who’s first?”
A wave of students groaned and looked away.
“Alice!” Kettleburn barked cheerfully, “You look radiant this morning, dear girl, start us off!”
Alice Fortescue stepped forward with a slightly embarrassed smile and held up a sleek silver tabby cat with a pink collar.
“This is Honoria,” she said, stroking the feline’s head. “She’s been with me since first year. She's very sweet, and she likes jazz.”
“She’s cute,” Marlene nodded approvingly. “But she looks like she’d stab me in my sleep.”
“She’s a Slytherin’s cat born into a Gryffindor dorm,” Alice agreed, amused. “She’s seen things.”
Next came Evan Rosier, who had a sinister-looking crow perched on his shoulder. The bird immediately screeched, “DIE!”
“Oh, he talks,” Evan said casually.
“He screams,” muttered Remus, flinching.
“His name’s Vesper. He only says things I’ve said near him.”
“That explains it,” Frank said, warily.
Peter stepped up, arms full of what looked like a wriggling tangle of... slime?
“This is Mungus!” he said proudly.
“Is it alive?” Lily asked, recoiling.
“Of course it is! He’s a Flubberworm–Horklump hybrid,” Peter said. “Illegally crossbred. He’s got 76 tiny legs and no discernible front.”
“Why is it pulsing?” Gideon asked.
“It likes attention,” Peter beamed.
Everyone shuffled a good two feet back.
“Right, thank you, Peter, that’s deeply disturbing,” Kettleburn said, jotting something down. “Next!”
Pandora Rosier, not to be outdone, sauntered forward in a long coat with glittering eyeshadow and a deadpan expression. She reached into her pocket, whispered something in Parseltongue, and produced what looked like a baby basilisk. It blinked.
“Oh what the actual fuck,” Sirius muttered.
“This is Lulu. She's venomous but shy,” Pandora said in her calm monotone. “She only eats live meat.”
“You’re not allowed to have that,” said Lily.
“Then I suppose you should call the authorities,” Pandora murmured, slipping Lulu back into her coat with a whisper.
More students followed—James had his family’s owl who kept flying directly into Kettleburn’s head. Lily had a toad. Remus shyly presented a rescued puffskein named Percy. Marlene brought a sugar glider that clung to her earring. Frank had a toad he’d glamoured to look like a tiny lion. Fabian and Gideon insisted they co-owned a miniature manticore plush that they’d bewitched to bite anyone who insulted Fabian’s hair.
Eventually, only one boy remained.
Regulus Black.
He stood near the back, arms folded over his slim chest, chin high, the sun catching the silver crest on his robes. Unlike the others, he hadn’t produced a crate or a carrier or a wriggling pillowcase. His bag sat calmly at his feet. He hadn’t moved.
“Mr. Black?” Kettleburn prompted.
“Oh,” Regulus said silkily, “I’m last? How quaint. The grand finale.”
Sirius groaned. “Of course you think you’re the finale.”
“Because I am,” Regulus replied without looking at him. He bent with careful grace, drew open his bag—and pulled out a packet of some strange, crinkly, foil-wrapped snack with foreign lettering across the front.
Everyone squinted.
“...What the hell is that?” Mary asked.
“They’re called Yap Chips,” Regulus purred, turning the bag in his fingers like a villain in an advert. “Imported from somewhere far more refined than this damp rock of a country. Hard to find. Delicious. Crunchy. Addictive.”
“Not a pet,” Lily pointed out.
Regulus’ grin was slow. Sharp. Dangerous. He peeled open the top of the bag with a practiced flair and fished one out between two long fingers, holding it up to the sun.
“Well. Not your pet.”
Then he looked directly at Sirius.
There was a flicker in Sirius’s expression. Barely perceptible, but for those who knew him—his friends, the Gryffindors—too perceptible.
His back stiffened. His hands clenched. His pupils dilated. His shoulders twitched like he’d just heard an electric guitar solo from across a battlefield. A bead of sweat formed at his temple.
“...No,” Sirius said quietly.
“Oh yes,” Regulus cooed, stepping forward, slowly. “It’s been years, hasn’t it, Siri? I haven’t brought these out in ages. Our childhood snack of choice. The one Mother said we were never to have. The one you loved more than life itself.”
James turned. “Wait… wait wait wait. Sirius loves those?”
“I don’t—” Sirius croaked, his voice breaking like a thirteen-year-old. “I don’t. I don’t care. They’re gross. Foreign. Probably poisoned—”
“Sit.” Regulus snapped, his voice dark and rich with command.
Sirius froze. His whole body trembled like a taut wire.
Then, to the stunned horror of every person present—he sat. On the grass. Legs tucked, palms flat. Like a well-trained puppy.
Gasps.
James screamed.
“WHAT THE FUCK.”
“Good boy,” Regulus said sweetly, tossing him a Yap Chip.
Sirius caught it. Devoured it in under a second. His eyes rolled back in bliss.
“Now roll over.”
“Sirius—no—” Remus began.
But it was too late.
Sirius Black was on the ground, flopping onto his back, wriggling like a damn golden retriever on bath day.
Peter wheezed. “I’m going to die.”
“Play dead,” Regulus purred.
THUD. Sirius flopped, tongue out, arms limp.
“Oh my god,” Lily whispered, “He’s broken. He’s actually broken.”
Regulus took a slow, arrogant step closer, bending down over his brother. “Speak.”
“Arf,” Sirius whispered.
“Louder.”
“ARF ARF,” Sirius barked, frenzied.
“Beg.”
Sirius rolled back to his knees, eyes wide, panting, tongue lolling, shaking. “Please,” he whimpered. “Please, Reggie, just one more—”
Regulus grinned with devilish delight and dropped another chip into Sirius’s waiting mouth.
“Good boy.”
The world exploded.
Marlene screamed. Gideon fell over. Pandora burst out laughing, which had never happened in recorded history. Kettleburn dropped his clipboard and whispered, “My god.” Evan was crying. Crying. Peter nearly threw up from laughter. Lily looked like she wanted to hex someone and wasn't sure who. Barty was just staring, his mouth twitching like he was experiencing his first emotion. Remus was clutching James’s sleeve, stunned.
“Sirius,” James gasped, “you’re a DOG. He made you his DOG.”
Sirius didn’t respond. He was too busy pawing gently at Regulus’s leg for another snack.
Regulus tilted his head. “Should I make him fetch? Or shake? Or do the one where he stands on his hind legs and claps—”
“I SWEAR TO GOD,” Sirius snapped, crumbs falling from his mouth, “If you tell them about the clapping trick I will—”
“SIT.”
Sirius immediately sat.
“STAY.”
Sirius froze in place, twitching.
Regulus turned to the class with a smile like a knife dipped in honey.
“My pet, Professor,” he said, smug and triumphant. “I trained him myself.”
Kettleburn, silent for once, just nodded slowly.
“Well,” he murmured. “Ten points to Slytherin.”
“You’re so good, Siri,” Regulus crooned in a syrupy baby voice, crouched beside his older brother, stroking his head like a prize-winning corgi. “So clever. So obedient. Who’s my good boy?”
Sirius barked once, tailbone wagging like he had one.
James was on his knees, clutching Remus like he’d just witnessed the second coming of Merlin. “This isn’t happening. This can’t be happening.”
“It is,” Remus muttered, wide-eyed. “It so is.”
Regulus dusted off another Yap Chip, holding it up just above Sirius’s mouth. “Say ‘I’m a mutt and I belong to you.’”
Sirius panted.
“Sirius, don’t,” Lily pleaded.
“I’m a mutt and I belong to you,” Sirius said immediately, eyes locked on the treat.
Regulus grinned. “Good boy!” He popped the chip into his brother’s mouth, then gave his head a vigorous little ruffle. “Who's my sweet slobbery little mongrel? Who’s my messy, hairy, obedient, horny little puppy—”
“I hate how specific that was,” Frank whispered.
Dorcas was filming everything with a handheld camera she’d conjured out of nowhere. “This is art. This is history. This is my thesis.”
Pandora clapped softly, expression unreadable. “This is romantic.”
“I’m gonna be sick,” Marlene muttered.
“I’ve got so many questions,” Fabian said.
“I’ve got none and I like it that way,” Gideon replied.
“I’ve got an answer,” Barty cut in dryly, “And the answer is Regulus wins.”
Sirius was now flopped on his belly, licking his palm like it was a paw.
Peter stared in open horror. “...How long has this been happening?”
“Oh, years,” Regulus said airily, adjusting his cufflinks. “Since we were little. Seven? Eight? Maybe six.”
“WHAT?” the Gryffindors screamed in unison.
“It started because we weren’t allowed pets,” Regulus went on, tone dreamy, stroking Sirius’s hair with fond, calculated cruelty. “Our parents said animals were beneath us, that we weren’t to dirty the house with them. I wanted a puppy more than anything. I was so distraught. Threw a tantrum. Cried for days. And then…” He turned to Sirius with a wicked grin. “My big brother decided to cheer me up.”
James blinked. “You mean this was Sirius’s idea?!”
Sirius barked, looked up, and whined, “He was so sad…”
Regulus beamed. “Isn’t he sweet?”
“So what,” Mary asked slowly, “he just started acting like your dog?”
“Literally got down on all fours and followed me around the house barking,” Regulus said smugly. “I was a grieving child. Naturally, I went with it. Fed him scraps under the table. Taught him tricks. Named him Starwhiskers. We never told our parents. We used to sneak into the gardens at night so he could pee on the roses.”
“REG!” Sirius hissed, ears red.
“I made you shit in the hydrangeas, don't pretend you forgot.”
Marlene screamed.
“You’re fucking lying,” Remus said, sounding deeply unwell.
“I fed him from a bowl for a week,” Reg continued proudly. “Used to sprinkle bacon bits in it. Even stuck a leash on him. Once I charmed a shock collar—just to see what would happen!”
“YOU MONSTER!” Lily shouted.
“I liked it!” Sirius barked defensively, tail wagging.
“YOU’RE A FREAK,” Frank howled.
“I thought we knew everything about Sirius Black,” James said hollowly. “But I didn’t know this.”
“Fetch,” Regulus said suddenly, hurling another Yap Chip into the grass.
Sirius took off like a blur, bolting on all fours across the enclosure. He skidded, pounced, ate the snack off the ground, then trotted proudly back, tailbone wiggling.
Regulus cackled, absolutely manic with delight. “What a good dog! What a stupid, food-driven, drooling little hound! C’mere, baby, give me a kiss—”
Sirius leapt. Tackled his brother flat into the grass with a loud oof, tailbone thumping like a metronome of shame. Everyone watched, open-mouthed, as Sirius went full puppy mode—rolling on Reg, nuzzling his chest, licking his face.
Regulus shrieked. “Get off me you absolute beast!”
“Nope,” Sirius said cheerfully, licking his brother’s cheek. “Missed my baby brother.”
“You’re crushing me,” Reg wheezed, trying to shove him off. “You’re too big, you floppy brute—”
Sirius just licked his neck. “You smell nice. Like spite and shampoo. Missed my master.”
“Don’t call me that in public!”
“You love it,” Sirius whispered, lips ghosting Reg’s ear.
“GET OFF—”
Reg’s protest cut short with a glare. “Are you hard? AGAIN?!”
The entire class collectively froze.
Sirius grinned, sly and unrepentant. “Oops.”
“You disgusting mutt,” Reg growled, trying to wriggle out from under him. “I told you not to do this in front of people!”
“Oh c’mon, Reggie baby, it’s not the first time,” Sirius purred. “You’re so good at taking a knot. And I’m in rut—you know you’re the only one who can help me…”
Pandora actually fainted.
Mary screamed and tried to climb Marlene like a tree.
Dorcas shrieked, “EXPLAIN THE ‘FIRST TIME’ RIGHT NOW.”
“I won’t!” Reg wailed, pounding on Sirius’s chest. “GET OFF ME YOU STUPID DOG.”
“I’ll stop if you give me another snack,” Sirius offered sweetly, wiggling his hips just enough to make Reg screech again.
Regulus looked to Kettleburn like he was begging for divine intervention. “DO SOMETHING!”
Kettleburn, hands shaking, whispered, “I’m too old for this shit.”
Barty Crouch Jr. just clapped slowly. “Bravo. The leash was symbolic.”
Sirius had officially lost his damn mind.
He was all smirks and slurred coos now, towering over Reg like a Great Dane with no sense of boundaries. Lips brushing his baby brother’s ear, hands slipping around Reg’s waist like he belonged there—like he'd always belonged there—nuzzling and licking and goddamn whimpering like some desperate, horny stray.
“C’mon, Reggie,” Sirius murmured, nipping lightly at Reg’s neck as his hips lazily pressed in with entirely too much intent. “You’re so pretty when you squirm. So fucking perfect. My favourite little toy. Can’t I have a treat too?”
Regulus shoved at him. “Get off me, mongrel!”
“I want you as my treat,” Sirius whispered, breath hot, voice sing-song and filthy. “Wanna eat you up. Wanna feel your pretty little cunt on my tongue—wanna go doggy style and rail you so dumb you can’t even spell Arithmancy, baby—”
“YOU ARE IN PUBLIC,” Reg shouted, face bright red, trying to kick him off.
“Mmhm. Public’s fun.” Sirius kissed his cheek, then his temple, then his mouth. Sloppy and grinning and so obviously enjoying the chaos. “Want you sitting on my face. Want your thighs around my ears, want you whimpering my name while I fuck the brat outta you—”
“BAD DOG!” Reg yelled, smacking him across the head.
Sirius yelped and whined dramatically, tongue out, eyes wide.
“Down, boy!” Reg snapped, bopping his nose with two fingers. “Bad. Dog. You get nothing when you act like this.”
Sirius growled and then smirked, eyes gleaming with dangerous heat. “But I like it when you scold me. Makes me wanna hump your leg. Do it again. Tell me I’m bad.”
“YOU ARE BAD!” Reg shouted, trying to crawl away as Sirius followed like a predator on all fours, purring and pawing and nuzzling his hip.
Everyone else?
Absolutely, irreversibly losing their fucking minds.
“THIS IS NOT A FAMILY DYNAMIC!” Lily shrieked, clutching Marlene’s arm like a lifeline.
“I KNEW HE WAS INTO FREAKY SHIT BUT THIS IS ACTUALLY INSANE!” James howled.
“Is this still Care of Magical Creatures or has it become Care of Your Unhinged Brother?” Remus deadpanned, staring into the void.
“Honestly this explains so much,” Peter muttered. “Sirius always did have big dog energy.”
“He used to lick me when he was drunk,” Frank whispered. “I thought it was a joke.”
“I saw him chew through a shoe once,” Marlene whispered back.
Sirius cooed, “You gonna let me breed you, Reggie?”
Reg let out the most indignant screech anyone had ever heard. “SIRIUS ORION BLACK.”
“Wait—” James interrupted, jaw dropping as something clicked. “Wait. Wait. You’re always talking about how you love chasing cats. You bark when you sleep. You drool over tennis balls. You get weirdly territorial about your bed. OH MY GOD.”
Remus blinked. “...He's the dog animagus.”
Peter smacked his forehead. “Padfoot. Of fucking course.”
Everyone went dead silent.
Sirius froze, Yap Chip crumbs on his lip, one hand mid-squeeze on Reg’s ass.
“...Fuck.”
Reg blinked.
“WHAT?!” Regulus screeched.
“You’re a WHAT?” Lily yelled.
“A FUCKING DOG?!” Frank choked.
“You bitch!” Reg shouted, shoving Sirius again. “You’re literally a bitch!”
“Can’t believe I forgot I’m actually an animagus,” Sirius muttered, laughing awkwardly. “It was supposed to be secret.”
Pandora’s eyes glittered like chaos incarnate. She clapped her hands and screamed with joy. “OH MY GOD. THIS IS SO ROMANTIC. YOU’RE BOTH ANIMAGI.”
Reg, blinking, turned sharply. “Pandora!”
Sirius stared at her too. “Wait. What.”
“Oh!” Pandora beamed, like she’d just remembered the weather. “Did I forget to mention? Regulus is one too.”
SCREEEEEAAAAAAM.
“What the FUCK?” James bellowed. “EVERYONE IS HIDING SECRETS!”
“I knew you were weirdly flexible,” Dorcas yelled at Reg.
“YOU NEVER SAID,” Sirius barked. “WHAT ARE YOU?”
Reg tried to speak. Pandora beat him to it.
“A spotted hyena!” she sang. “So fitting, right? Mean. Loud. Spiteful. Makes horrible noises when it laughs. Looks cute, actually horrifying. Alpha energy. Absolutely chaotic. Kind of a man-eater.”
Regulus shrieked in betrayal.
“YOU TRAITOR! YOU PINK-EYED COCKROACH OF A GIRL—”
Pandora giggled and did a spin. “It’s true, darling. I’ve seen it. Little hyena pup with freckles on his back and a stupid prancy walk and sharp little teeth—he’s adorable.”
“YOU SWORE TO NEVER TELL ANYONE.”
“I lied.”
Sirius was staring.
“...A hyena?” he asked, blinking. “Seriously?”
Reg glared at him. “Yes, and?”
Sirius licked his lips. “That’s so fucking hot.”
“FUCK YOU.”
“Please,” Sirius whispered, pressing his forehead to Reg’s. “Let’s shift together. Let’s frolic. Let’s hunt a rabbit and destroy someone’s flower bed. Let’s—”
“Shut the fuck up!” Regulus screeched.
“Hyenas and dogs can mate, right?” Pandora asked helpfully.
“SHUT UP, PANDORA.”
“WHY DOES THAT MATTER?!” screamed Lily.
“I’m going to faint,” Frank said weakly.
Fabian was on his knees crying from laughter. “He’s a dog. He’s a hyena. This is literally a twisted, feral fairytale romance and I want to die.”
Kettleburn, pale and shaking, sat down in the dirt. “I used to have tenure,” he whispered. “I used to be respected.”
Sirius licked Reg’s cheek again.
Reg tried to slap him.
Missed.
And barked.
By instinct.
Everyone went feral.
“YOU BARKED,” James screeched.
“YOU BARKED BACK,” Marlene screamed.
“WE'RE IN HELL,” Lily cried.
And through it all, Sirius and Regulus lay tangled on the grass, rolling and growling and yipping like the feral, cursed, animagus brothers they were.
Somewhere in the distance, a Yap Chip bag rustled in the wind. And Hogwarts was never the same again.
