I used NovelAI's unlimited gen membership for $25 a month. Note that "unlimited" is kind of a lie, it's only unlimited if you're under a certain resolution and only if you're not using any of the advanced features. Upscaling and other features cost the on-site currency, which the membership gets you 10000 a month. That should be more than enough for a month, but you can burn through it quickly since NAI gens so quickly.

The Great Fox’s medical bay was a private oasis of soft blue lighting and plush white bedding, the stars outside the viewport swirling in endless silence. Fox McCloud had carried Krystal here after the last, earth-shattering orgasm, her body a trembling, cum-soaked wreck. Now she lay sprawled across the wide bed, one hand cradling the impossible, globe-sized swell of her belly while the other lazily kneaded her own leaking breast.

Her suit was long gone. Only a thin blue stretch of fabric remained, pulled so tight over her engorged curves that every inch of skin was visible. Her belly—Fox’s monstrous, cum-inflated masterpiece—dominated the entire frame, stretching the fabric to its limit and forcing her belly button out in a perfect, swollen nub. It was bigger than her head, bigger than her torso, bigger than anything human or even most full-grown foxes could carry. The skin was shiny, taut, and glistening with a thin layer of sweat, covered in faint white stretch marks that only made the glory of it more obscene.

Fox stood at the foot of the bed, still fully clothed in his blue flight suit, cock already rock-hard and tenting the fabric obscenely. His green eyes were dark with lust as he watched his lover’s face.

“Krystal… fuck,” he murmured, voice low and reverent. “You’re glowing. That belly… it’s bigger than your whole body. My cum did that. Hundreds of my loads. Dozens and dozens of fox cubs in there now. And you’re still taking it like the perfect little breeding slut you are.”

Krystal’s green eyes fluttered open. A soft, seductive smile curved her lips, cheeks flushed pink. She bit her lower lip, tail flicking lazily behind her as she looked up at him with pure affection and filthy hunger.

“Mmm… Fox… you did this to me,” she purred, voice husky and breathless. Her hand slid lower, gently pressing into the massive dome of her belly. “It’s so full of you… I can feel every single drop, every drop of your potent seed. My womb is swollen and stuffed and I’ve never felt so… so pregnant. So much of you inside me.”

Fox stepped closer, boots silent on the padded floor. He reached out and stroked the underside of her belly with one clawed finger. The skin was warm, heavy, and impossibly tight. A faint, wet gurgle echoed from inside the orb as he pressed down.

“Feel that?” he growled, voice dropping an octave. “That’s the sound of your belly working, Krystal. All those fox kits shifting around in there, getting even bigger with every drop of my cum. I kept pumping you full until you couldn’t take any more. And now look at you… lying here in my bed, belly bigger than me, tits leaking milk because your body’s overstimulated from carrying my load. You’re the most beautiful hyper-pregnant fox in the galaxy, and I’m never letting you go.”

Krystal moaned softly, arching her back so her massive breasts lifted. Thin streams of white milk beaded at her nipples and dripped down the sides of her swollen chest.

“Fox… you’re so good to me,” she whispered, eyes half-lidded in bliss. “Every time you fill me, it makes me bigger. I feel so heavy… so full… like I’m going to burst with how much of you there is. But I don’t want to stop. Keep breeding me. Keep knocking me up until my belly is permanently huge and my pussy is always leaking your cum.”

She reached down with her free hand and gently tugged at the front of his flight suit, freeing his thick, throbbing cock. It sprang out heavy and veined, the knot already swelling at the base. A thick bead of precum glistened at the tip.

“Still so hard for me,” she murmured, stroking him slowly. “Even after all that… you want more, don’t you? You want to feel your belly again.”

Fox’s smirk was pure wolf. He climbed onto the bed, careful not to jostle her too much, and settled between her thighs. The scent of her—sweet musk mixed with the thick, heady aroma of fresh cum—filled the air like a drug.

“Always,” he said, voice rough. He rubbed the fat head of his cock along her swollen lips, coating himself in her juices and the lingering remnants of his earlier loads. “Feel that, Krystal? That’s me getting ready for round… whatever this is. You’re so wet. Your pussy’s stretched wide open just from carrying my cum.”

He pushed in slowly, inch by thick inch, watching her belly shift and stretch with every centimeter. The head nudged the thin, overstretched wall of her womb and a fresh wave of milk spurted from her nipple.

“Ahh—!” Krystal gasped, back bowing. “Fox—! It’s so deep— I can feel you pressing against all my babies— they’re moving, Fox, I can feel them kicking— ah, it’s so good—!”

Her pussy clenched around him like a vice, milking his cock. The wet, obscene sound of him sliding deeper filled the bay. Fox groaned, ears flat with pleasure, and started thrusting—slow, powerful rolls at first, letting her feel every ridge and vein.

“Listen to you,” he panted, voice breaking. “So full of me… your belly’s jiggling with every thrust. Feel that? That’s my cock filling you up again. Feel how your pussy is gripping me— like it never wants me to leave. I’m gonna pump another load into this perfect, cum-drenched womb of yours.”

Each stroke made her belly bounce and gurgle softly. The pressure on her cervix was intense, sending sparks of pleasure-pain through her. Fox reached down and rubbed slow circles around her stretched clit while he fucked her, feeling the way her inner walls fluttered.

Krystal’s head thrashed against the pillow, blue hair spilling everywhere. Her free hand clutched at Fox’s shoulder, claws digging in.

“Fox— I’m— I’m gonna come just from this— from you fucking me while I’m this pregnant— ahh—! My belly— it’s so full— I can feel your knot pushing against all those fox cubs—!”

Fox leaned down, mouth latching onto one of her leaking nipples. He sucked hard, tongue swirling, while his hips snapped faster. The wet squelch of his cock moving inside her was loud, filthy, rhythmic. Her milk leaked steadily into his mouth, warm and slightly sweet, making him groan around her breast.

“Drink it, Krystal,” he growled around her nipple. “Drink your own milk while I breed you. You’re such a good little hyper-pregnant slut. My cum’s making you so sensitive… I can feel your pussy pulsing around me.”

The orgasm hit her like a tidal wave.

“Fox—! I’m— I’m cumming—!” Krystal screamed, voice cracking. Her belly tightened violently. “It’s— it’s starting again— your cum— it’s coming—!”

Thick, heavy ropes of Fox’s seed erupted into her womb with every thrust. The first powerful spurt alone made her belly inflate another inch, the skin stretching even tighter, veins standing out more clearly. The second, third, and fourth jets followed in rapid succession, each one louder than the last, forcing her womb to bulge outward visibly.

“G-Gallons!” Fox snarled, voice raw with pleasure. “That’s it— take every drop— every single fox cub in there is gonna grow big and strong because of this load—!”

The bed creaked under the force of his thrusts. Cum overflowed instantly, gushing out around his knot in thick, creamy waterfalls that splattered across her thighs, his fur, and the sheets. Her belly ballooned outward, shiny and drum-tight, the size now even more absurd—easily three times her body. Milk continued to leak in steady streams as her overstimulation peaked.

Krystal’s eyes rolled back, tongue hanging out in a lewd, panting expression. “Fox—! I love you— I love your cum— fill me— breed me— make my belly even bigger— I want to be pregnant forever— ahh—!”

Fox fucked her through the orgasm, relentless, driving his knot flush against her cervix and unloading again and again. The cockpit bay filled with the wet, obscene sounds of creampie after creampie. The air was thick with the scent of sex, cum, and milk. Every thrust forced more of her juices to mix with his seed, dripping in long strands down to the puddle forming beneath her.

When Fox finally collapsed, panting, cock still buried deep and knot locked tight, Krystal was a trembling, blissed-out mess. Her belly was so swollen and round it rested against his chest, gurgling softly with the pressure of gallons inside. Her breasts were heavy, leaking, and sore, while her pussy was a ruined, puffy, constantly squirting mess.

“Fox…” she whispered, voice hoarse and dazed, one hand still gently rubbing her massively distended dome. “I’ve never been so full… I can feel all of you in there… dozens, hundreds of your babies… they’re all growing because of your seed. My belly’s so big… so heavy… and I’m still leaking milk and you’re still hard inside me. I love it. I love being your hyper-pregnant fox.”

Fox nuzzled her swollen belly with a kiss, then looked up at her with that smug, satisfied grin.

“Every day for the rest of our lives, Krystal,” he murmured, voice rough with promise. “I’m never pulling out. I’m going to keep pumping you full until your belly is permanently huge and my kids are squirming around in there. You’re mine. My perfect, cum-inflated breeding toy. And I’m never letting you go.”

Krystal smiled, eyes fluttering shut in pure contentment, her tail curling around his waist as she pulled him closer.

“Promise?”

“Promise,” he growled, already feeling his knot starting to swell again.

Outside the viewport, the Great Fox continued its silent flight through the stars. Inside the medical bay, the two lovers stayed locked together, Fox’s cock still buried deep in her cum-stuffed womb, her massively swollen belly resting heavily against his chest. Soft, satisfied moans and gentle kisses filled the air, mixed with the faint, constant trickle of thick seed still dripping from her wrecked pussy and the soft, rhythmic gurgle of fox cubs kicking inside her.

And somewhere deep inside that impossible, hyper-pregnant belly, Fox’s potent seed was already taking root— a promise of many more loads, many more cubs, and many more nights of breeding bliss to come.