Chapter 4: The Knot Takes Hold
The door was still locked. The room still smelled like them. And Birch couldn't move.
He tried to pull back, to put some space between his body and Willow's, to catch his breath and figure out what the fuck had just happened. But when he shifted his hips, something pulled. Something held.
"What the—" He looked down.
His sheathe was still wrapped around the head of Willow's cock. Not just touching. Not just resting. Sealed. The opening had cinched tight around her shaft, just below the swollen ridge of her knot, and no amount of tugging was going to change that.
"Oh fuck," he said.
Willow looked down too. Her eyes were still glassy, her chest still heaving, but when she saw what was happening, a laugh bubbled up out of her. Low and rough and genuinely amused.
"Guess we're stuck," she growled.
"This isn't funny."
"It's a little funny."
"It's—" He tried to pull away again. The sheathe held firm, and the sensation of her cock shifting inside him sent a jolt of pleasure straight up his spine. "Fuck."
Willow's hands found his hips. Her claws were still out, still sharp, and they pressed into his skin just hard enough to make him gasp.
"Stop squirming," she said. "You're gonna hurt yourself."
"I'm not—"
"You are." She stepped forward, forcing him backward. His feet stumbled, and his back hit the edge of the desk. The old wood creaked under his weight. "Just relax."
"Relax? Willow, we're—we're fucking stuck together. My—" He gestured helplessly at his crotch. "My thing won't let go of you."
"I know." She was smiling now. That sharp, dangerous smile he'd seen a hundred times in class, the one that meant she was about to do something reckless. "Kind of hot, honestly."
"Kind of—"
She kissed him.
It was a rough kiss, hungry and demanding, and he melted into it before he could think. Her tongue pushed into his mouth, and he tasted himself on her—salty and bitter and strange—and something about that made his cock twitch against his belly.
When she pulled back, her eyes were dark.
"I want to fuck you properly," she said. "Not just standing here. I want to bend you over this desk and fuck you until you can't walk."
Birch's mouth went dry.
"You—"
"I've been thinking about it since last night." She pressed closer, and her cock shifted inside his sheathe again. He whimpered. "Since I saw what you've got between your legs. Since I felt what you did to me in that theater."
"That was—"
"I know what it was." She cut him off. "It was the hottest thing that's ever happened to me. And I want more."
She didn't wait for an answer. She just grabbed him by the hips and lifted.
He was heavy—he'd always been heavy, thick and solid and bearish—but she lifted him like he weighed nothing. Her new muscles bunched and flexed, and she hoisted him onto the edge of the desk like he was a sack of feathers. The whiskey bottle toppled and rolled, spilling amber liquid across the yellowed pages of the textbook. Neither of them cared.
"Hands on the desk," she ordered.
He obeyed.
The wood was cold under his palms, rough with carved initials and old stains. He gripped the edge, claws digging in, and looked back over his shoulder just in time to see Willow step up behind him.
Her cock was still buried in his sheathe. The angle was different now—deeper, somehow—and when she shifted her weight, he felt her knot press against his opening. Hard. Insistent.
"Ready?" she asked.
"Willow—"
"Answer the question."
"Yes." The word came out strangled. "Yes, I'm ready."
She pulled back.
The sensation was exquisite torture. Her shaft slid through his foreskin like it was made for it, the tight seal of his sheathe dragging along every inch of her. When she was almost all the way out—just the tip of her cock still caught inside him—she stopped.
And then she slammed back in.
"FUCK!" Birch's scream echoed off the walls.
She didn't stop. Didn't give him time to adjust. She just fucked into him, hard and fast and relentless, and every thrust sent shockwaves of pleasure radiating through his entire body. Her knot ground against his opening, never quite pushing inside, always just on the edge of too much.
"That's it," Willow growled. Her voice was a deep rumble, barely human. "Take it. Take all of it."
He took it.
She fucked him through the first orgasm before he even realized what was happening. His cock jerked and spasmed against his belly, spurting ropes of cum onto the dusty floorboards, and his whole body clenched around her like a fist. She groaned, deep and satisfied, and kept going.
"One down," she said. "Two to go."
"What—"
She fucked him through the second one too.
This time, he felt it coming. The pressure built slowly, coiling in his balls, spreading through his groin, until every thrust of her cock pushed him closer and closer to the edge. When he finally came, it was with a scream that turned into a sob—his release flooding out of him, thick and hot, splashing onto his thighs and the desk and the floor.
Willow's cock was still hard inside him. Still fucking. Still relentless.
"Fuck," he panted. "Fuck, Willow, I can't—"
"You can." She leaned over him, her chest pressing against his back, her teeth grazing his ear. "You're gonna give me one more. And then I'm gonna fill you up so full you'll be leaking for days."
"I can't—"
"You can." She bit down on his shoulder.
He came again.
This time, it was almost too much. His vision went white, and his whole body seized up, and he felt something give inside him—his sheathe overflowing, Willow's cum and his own mixing together, dripping down his thighs in thick, sticky ropes. His cock twitched and spasmed, spurting weakly against his belly, completely spent.
And still, Willow fucked him.
"One more," she growled.
"No—"
"One more, Birch. I want to feel you break."
She fucked him harder. Faster. Her claws dug into his hips, and her knot ground against his opening with every thrust, and the sounds she was making were pure animal—grunts and growls and low, rumbling moans.
He broke.
The fourth orgasm ripped through him like a storm, and he screamed—really screamed, loud enough that anyone passing by in the hallway would have heard. His whole body convulsed, and his cock sprayed nothing but clear fluid, and his sheathe clenched down around Willow's shaft so tight that she roared.
"FUCK!" she shouted. "FUCK, YES—"
She came.
He felt it—every pulse, every spurt, flooding into him. Her release filled his sheathe until it overflowed, dripping down his thighs and pooling on the desk beneath him. Her knot swelled, locking them together again, and she collapsed against his back, breathing hard.
They stayed like that for a long moment. Panting. Trembling. Spent.
Then, slowly, Willow pulled free.
The loss was almost unbearable. His sheathe gaped open, empty and slick, and he could feel their combined fluids leaking out of him in a steady stream. He whimpered, and she shushed him, her hand gentle on his back.
"It's okay," she murmured. "I've got you."
He turned around. His legs were shaking. His whole body was shaking. But when he looked at Willow, she was smiling—that soft, secret smile he'd only seen a few times before, the one that made his chest ache.
"We need to get out of here," she said. "Before someone finds us."
"I don't think I can walk."
She laughed. "I'll carry you."
"You can't—"
She scooped him up like he weighed nothing.
He yelped, grabbing onto her shoulders, and she carried him across the study room like a bride over a threshold. His cum and hers dripped onto the floor, leaving a trail of evidence behind them, but she didn't seem to care.
"Where are we going?" he asked.
"My place." She nudged the door open with her foot. "We've got a lot to figure out. And I'm not done with you yet."
"What do you mean?"
She looked down at him, and her eyes were dark and hungry and full of something that made his breath catch.
"I mean," she said, "whatever's happening to us? It's not done. I can feel it. Can't you?"
He could.
The substance was still there—still working, still changing things. His sheathe was already starting to close, to reform around the empty space, and he could feel something shifting in his balls. Something swelling.
"Yeah," he said. "I can feel it."
She smirked.
"Good. Then let's go. We've got work to do."
She carried him out of the room, down the empty hallway, past the rows of locked doors and flickering lights. The morning was still gray, still quiet, and no one saw them go.
But if anyone had been watching, they would have seen two figures—one tall and bearish, one taller and built like a tank—moving through the shadows with a purpose that was no longer entirely human.
And they would have seen the way their bodies kept changing. Growing. Shifting.
Becoming something new.
The hallway was empty. The morning was still gray. And somewhere in the distance, a bell rang.
Class was starting.
Neither of them looked back.
Willow carried him through the service corridors, the ones that ran behind the main lecture halls like veins under skin. No one used them this time of morning. No one would see the two of them—her still half-transformed, him dripping and spent—moving through the shadows toward the male dormitory.
"You're heavy," she said.
"You're the one who picked me up."
"Shut up."
Her boots echoed off the concrete, and his bare feet swung uselessly against her thighs. His pants were still tangled around one ankle, his cock still hanging out, still slick with everything they'd done. He should have felt embarrassed. He didn't. He felt raw. Open. Like someone had peeled back a layer of skin and left the nerves exposed.
They reached his door. She set him down, and his legs almost gave out.
"Keys?" she asked.
"Pocket."
She fished them out of his discarded sweats, still crumpled on the floor where they'd fallen earlier, and unlocked the door. The room smelled like him—cologne and sweat and something musky underneath. The bed was still unmade, the sheets still tangled, and the desk lamp was still flickering from the night before.
She pushed him inside and closed the door behind them.
"Pants off," she said.
"You first."
She grinned. "Bossy now?"
"I learned from the best."
She stripped without ceremony. Her pants were already ruined—the seam split, the denim soaked through with her own release—and she peeled them off with a wet, sucking sound that made him wince. Her underwear came next. They were soaked too, dark and clinging, and when she tossed them aside, her cock sprang free.
It was still thick. Still red. Still knotted at the base.
But something was different now. The tip had changed—the slit wider, the head flared, and around the base of her shaft, a new ridge of tissue had formed, glossy and tight.
"What the fuck," he breathed.
"Told you," she said. "It's not done."
She kicked her clothes into a corner and climbed onto his bed. The mattress groaned under her weight. She was bigger than she'd been this morning—taller, broader, heavier. Her tits had thickened too, low and full, nipples dark and hard. The hair on her stomach had spread, dense and coarse, trailing down to the thatch around her cock.
"Get up here," she said.
He kicked off his sweats. His own cock was still out, still half-hard, the sheathe retreating but not gone. He climbed onto the bed, and the mattress dipped under both their weights—two bears, muscle and fat and hair, sinking into the same hollow.
She pulled him down.
He landed on his back, and she was on top of him before he could blink. Her thighs pinned his thighs. Her stomach pressed against his stomach—soft and warm, thick with muscle underneath—and their guts smooshed together, skin sliding against skin.
"Fuck," she whispered. "You feel that?"
He felt it. Her cock was trapped between them, pinned against his own, and the heat of it was almost unbearable. Her sac hung low, heavy and dark, and it rested against his sac like they were made for each other.
"Rock with me," she said.
He did.
She ground her hips against his, slow and deliberate, and their cocks slid together in the wet space between their bodies. The hair on their stomachs tangled, and their balls kissed with every thrust, and the sensation was so good that his eyes rolled back in his head.
"Shit," he groaned. "Shit, Willow—"
"Shut up. Just feel it."
She rocked harder. Their sheathes—hers forming, his retreating—pressed together, and his cock slipped free of his foreskin again, fully hard, fully exposed. The tip bumped against her shaft, and a bead of precum welled up and smeared between them.
"Look at that," she said. "You're leaking already."
"You're one to talk."
She looked down. Her own cock was slick, the tip glistening, and a thin strand of precum stretched between her slit and his stomach. She laughed, low and rough.
"We're a mess," she said.
"Good mess."
She rocked against him again, and their cocks slid together, the friction maddening. He reached down between them, wrapping his hand around both shafts at once—not easy, with how thick they both were, but he managed. She hissed through her teeth.
"What are you doing?"
"Something I've wanted to do since last night."
He stroked them together, slow and tight, and she braced her hands on either side of his head and let him. Her eyes were half-closed, her mouth open, and every stroke pulled a low sound from her throat.
"Fuck," she whispered. "That's good."
"Wait."
He stopped. She opened her eyes.
"What?"
He pointed at the nightstand. "Top drawer."
She reached over him, her tits brushing his face, and pulled it open. Inside, nestled between a half-empty bottle of lube and a crumpled bag of chips, was a fleshlight. Black casing, clear sleeve, well-used but clean.
"Seriously?" she said.
"Seriously."
She grabbed it and sat back. Her cock bobbed against her stomach, still slick from his hand, and she looked at the toy like it was something new.
"You want me to use this?"
"I want you to watch me use it first. Then I want to watch you."
She raised an eyebrow. "Why you first?"
"Because I asked nicely."
She snorted but handed it over. He took it, popped the cap, and let a generous squeeze of lube drip down the sleeve. Then he wrapped his hand around his cock and guided it to the opening.
The first push made him gasp.
The sleeve was tight—tighter than he remembered, but he hadn't used it since before the change. His sheathe stretched around the opening, and his cock slid into the soft, ribbed tunnel like it was sliding into a body. He pushed until his balls rested against the plastic rim, then pulled back and pushed again.
"Fuck," Willow breathed. She was watching him, her hand wrapped around her own cock, stroking slowly. "That's hot."
"You want a turn?"
"Not yet."
She watched him fuck the toy. Every thrust made his whole body jerk, and his balls slapped against the casing with a wet thud. His cock was so thick that the sleeve bulged around him, the clear rubber stretching to accommodate his girth, and the sight made Willow's mouth water.
"Faster," she said.
He went faster.
She crawled forward, positioning herself between his legs, and pressed her sac against his. The heat of her—the weight, the hair, the sheer presence of her—made him groan. Her balls were tight against his, and with every thrust, they kissed and rolled together like they were trying to merge.
"Fuck," he grunted. "Your balls are so warm."
"Your ass is better."
"Shut up and watch."
She watched. She watched him fuck the toy with everything he had, watched his claws dig into the sheets, watched his face twist with pleasure. Her own cock was leaking freely now, precum dripping down her shaft and onto his thigh.
"Give it here," she said.
He didn't want to stop. But he pulled out, and the toy slipped free with a wet sound, and he handed it over. The sleeve was slick with his precum, and she took it like it was something sacred.
She lined it up with her own cock and pushed in.
The sound she made was guttural—half moan, half growl—and her hips bucked involuntarily. She fucked the toy with abandon, her balls swinging heavy, slapping against the base with every thrust. Birch watched, mesmerized.
"You look good like that," he said.
"Shut up."
"No, really. Your fat cock stretching that thing—it's a sight."
She growled, low in her throat, and kept fucking. Her cock was so thick that the sleeve strained around her, the rubber going white with tension. And her knot—the knot at her base—kept bumping against the opening, too big to enter.
"Fuck," she panted. "This thing is tight."
"Told you."
"I'm not gonna last."
"Then don't."
She fucked it harder. Her balls were swinging so heavy they almost hit Birch's, and their sacs kept brushing together, electric and warm. She was close—he could see it in her face, in the way her jaw clenched, in the way her rhythm was breaking down.
"Give it back," he said.
She pulled out and handed it over without hesitating.
He took it and pushed his cock inside. It was different now—slicker, warmer, full of her. Her precum had mixed with his, and the inside of the sleeve was coated in their combined fluids, and the sensation was so good that his eyes almost rolled back.
"Fuck," he groaned. "You feel that? It's so wet."
"I feel it."
"You made it wet."
"Fuck you."
He fucked the toy harder, faster, his hips slamming into it. His balls were drawn up tight, and every thrust made them slap against his own thigh, and he could feel Willow watching him, her hand on her cock, stroking in time with his thrusts.
"Look at you," she said, low and rough. "Fucking that toy like it's my ass."
"Maybe it is."
"Maybe you want it to be."
He bucked harder. The pressure was building, coiling in his balls, spreading up his spine, and he knew he was close. So close.
"I'm gonna come," he grunted.
"Cum in it," she said. "I want to see."
He roared.
The sound tore out of his throat, raw and animal, and his whole body convulsed. He came inside the toy—thick, hot ropes of it, filling the sleeve until it overflowed and dripped down his shaft. His hips kept jerking, kept pushing, and he could feel Willow's eyes on him, hungry and dark.
When he finally pulled out, the toy was a mess. His cum was everywhere—coating the inside, dripping from the opening, slicking his cock.
"Give it to me," Willow said.
He handed it over. She thrust her cock inside without hesitation, fucking into the wet heat of his cum, and the sound it made was obscene—a wet, sucking squelch with every thrust.
"Fuck," she gasped. "Fuck, that's—that's so good."
"I know."
She closed her eyes and fucked the toy, her balls slapping against her own thighs, and Birch watched her—watched the way her muscles bunched, the way her tits bounced, the way her lips parted around a silent moan. She was fucking the toy like it was the last thing she'd ever do.
Then he sat up.
"Wait," he said. "I want to do something."
She opened her eyes, hazy and confused. "What?"
He took the toy from her—gently, insistently—and wrapped his hand around her cock.
"Let me," he said.
She stared at him. Her cock was hard and slick and hot in his hand, and she was panting like she'd just run a mile.
"Birch—"
"Trust me."
He pushed the toy back onto her cock, but this time, he didn't let her do the work. He fucked her with it—driving the sleeve down onto her shaft, pulling it back up, fast and hard and relentless. She threw her head back and groaned.
"Fuck! Fuck, that's—"
"Good?"
"Don't stop—"
He didn't stop. He fucked her with the toy, and with every thrust, her balls slapped against his, and with every thrust, she got closer. She was whimpering now—actual whimpering, high and desperate.
"Please," she gasped. "Please, Birch—"
"Please what?"
"Make me cum. Please make me cum."
He did.
The toy broke.
It happened fast—the sleeve stretched past its limit, the rubber tearing with a sharp, wet ripping sound. Her cock burst through, and the half-destroyed toy fell away, revealing her shaft in its full, inhuman glory—red and thick and knotted, bursting free with a violence that left them both breathless.
"What the fuck," she whispered.
His cock burst next.
His sheathe tore open, stretched past its limit, and his own shaft sprang free—equally red, equally knotted, equally inhuman. He looked down at himself, at this new body, this new cock, and he didn't feel scared.
He felt hungry.
They collapsed back onto the bed, panting, sweating, their cocks spent and sore. Willow's shaft lay heavy on her inner thigh, still wet from the destroyed toy, still leaking a thin stream of cum that pooled on the sheets. His own cock mirrored hers—lying on his thigh, soft but still thick, still knotted at the base.
They stayed like that for a long time. Minutes. Maybe more.
Then Birch sat up.
"What are you doing?" Willow asked.
He didn't answer with words. He just crawled between her legs, and he lowered his body onto hers.
His cock slid against hers—skin on skin, hot and slick. He started humping her, slow and deliberate, frotting their shafts together in the mess of cum and sweat between their bodies.
Her balls slid against his. Her knot pressed against his. Her skin was warm, her body was heavy, and the sight of their cocks grinding together was enough to make his own twitch with interest again.
"You're serious?" she asked.
"I'm always serious."
He fucked against her, slow and steady, and the bed creaked beneath them. Their cocks slicked together, and their sacs kissed, and their hair grew in together.
Somewhere outside, the clock tower chimed.
Neither of them heard it.