The stable reeked of hay, sweat, and animal musk when Rex the German Shepherd slipped inside after dark. His tail wagged low and his hole already twitched from the filthy thoughts he'd been having all day.
Thunder the pony stood in the far stall, black coat gleaming, heavy sheath hanging thick between his hind legs. Rex knew that sheath. He knew what it hid.
"Been waiting for you, mutt," Thunder rumbled, voice low and rough. He turned, showing off the heavy balls and the tip of pink cock already pushing out. "You said you wanted it deep tonight."
Rex didn't answer with words. He dropped to all fours, shoved his ass up, and spread his cheeks with one paw. "Shut up and fuck me, pony. I want that fat cock splitting my hole."
Thunder snorted and stepped closer. His cock slid free fast, long, veined, and already dripping. The flared head looked obscene next to Rex's smaller frame. "Look at that greedy dog ass. Already winking for me."
He mounted without ceremony. Hooves planted on either side of Rex's body, the weight pressing the dog down into the straw. The blunt tip of Thunder's cock prodded between Rex's cheeks, smearing pre across the tight ring. Rex whined and pushed back. "Do it. Penetrate me. I need that pony dick inside."
Thunder thrust. The head popped past the tight muscle with a wet sound. Rex yelped, claws digging into the dirt floor as his ass stretched around the thick invasion. Inch after inch sank in, the flared head forcing his insides open. "Fuck, yes," Rex gasped. "Deeper. Split my gay dog ass wide open."
The pony didn't hold back. He drove the rest of his cock home in one hard shove, balls slapping against Rex's tail. The dog's belly bulged slightly from the sheer size. Thunder started fucking immediately, long, powerful strokes that pulled almost all the way out before slamming back in. Each thrust punched a moan out of Rex.
"Take it, you filthy slut," Thunder grunted, hips snapping. "Your hole's sucking me like it was made for pony cock." The wet squelch of lube and pre filled the stall. Rex's own cock hung hard and dripping beneath him, untouched, swinging with every brutal thrust.
Thunder's pace turned savage. He fucked like he wanted to ruin the dog, cockhead battering Rex's prostate on every stroke. Rex howled, ass clenching around the invading shaft. "Harder! Penetrate me deeper, you horny bastard. Fill my guts."
Sweat and pre ran down Rex's fur. Thunder's heavy balls slapped wetly against him. The pony's breathing grew ragged, his thrusts losing rhythm as his orgasm built. "Gonna flood that dog hole," he warned. "Gonna pump so much cum up your ass you'll leak for days."
Rex pushed back harder, taking every inch. "Do it. Breed me."
Thunder slammed in to the hilt and stayed there. His cock pulsed, jets of thick pony cum erupting deep inside Rex's stretched ass. The heat flooded him, belly swelling slightly from the sheer volume. Rex came untouched, his own cock spurting ropes across the straw while his hole milked the throbbing shaft still buried inside him.
They stayed locked like that, Thunder's weight pinning the smaller dog, cum leaking out around the base of his cock. Rex panted, ass still twitching. "Again," he begged after a minute. "Don't pull out yet. Fuck me with that load still inside."
Thunder chuckled darkly and started moving again, slower this time but just as deep, the wet sound of cum-slick fucking filling the night. Rex moaned and took every thrust, ass used and happy, exactly the way a horny pony and a needy gay dog were meant to spend the night.
