Rarity moaned out in pain as Spot's pelvis beat furiously against her now very sore nose. His massive paws squeezed her ears painfully tight as he held her head in place humping furiously against it; as his jagged dirty claws digging into the soft white skin of her inner ears. Rarity gagged a little as each thrust battered the tapered tip of his short but thick canine cock against her uvula. It was a constant fight not throw up, but Rarity had to keep fighting knowing that if she did Spot's huge knot that after slipping past her teeth had swollen so large that it pushed her mouth painfully wide, wouldn't let any of her sick escape her mouth. If Rarity threw up, she would just be forced to swallow it back down.
"Whiny mule should have never come back; we know how to deal with your now. Now you make better noises!" Rover rasped in delight as he lay under Rarity his paws gripping her shoulder blades and pulling her down, along his stomach as he thrust up into her batter teardrop cunt with his long cock. His knot was beating painfully against the thick pink lips of Rarity's cunt. They had worked her so hard that she didn't have the energy to clench against him and her pussy accepting the assault without protest.
Rarity moan of protest died with a gag as Spot yanked her head back towards him by her ears. Rover growled in anger at the smaller diamond dog and pulled her back down hard, his dirty claws leaving another line of red scratches on her back, and thrust into her with a savage buck of his hips. His knot slammed hard against Rarity's cunt, and she squeaked when his knot popped past her cunt lips. Spot yanked her forward again by her ears and Rover didn't resist, except to pull his hips back. He just smiled satisfactorily as his knot slipped free of Rarity's cunt with a wet pop and Rarity gag was interrupted by a muffled squeak.
Fido ignored his brothers' fighting re-secured his grip around Rarity's flanks, covering several long red scratches left by his claws, and hammered his knot against Rarity's pink pucker. While Rover and Spot had enjoyed tormenting their new work mule, Fido had had to work to gain access to her tight anus. They had been humping the mule for over twenty minutes by the time he'd gotten her ass licked thoroughly enough to enjoy himself, and now after almost a half hour of humping his knot was finally pounding against her pink donut.
Rover could have fun listening to Rarity's cries of pain as he popped his know in and out of her mule cunt. Once Fido was base ball sized know in Rarity's ass she'd be too stretched to take Fido's again. The truth was, Fido had swollen too big to try and knot a female, but that was a curiously he might extend only to a proper diamond dog bitch, not a whining mule like Rarity.
He slammed against her ass and grinned finally feeling her pucker stretch a little around his knot. He pulled back a little farther and slammed into her again, her hole yawning a bit more open. Growling unfavorably at the minor progress, Fido pulled a full inch of his red shaft out of Rarity's ass and slammed it back in. The mule let out a squeak past spot's cock that might have been caused by Fido's efforts, but the larger diamond dog didn't care.
He pulled back three inches this time and rammed himself back in. The mule's squeak was definitely for him this time as he stretched Rarity maybe an eighth of the way around his knot that time. It was hard to tell exactly since Fido's know was still swelling larger.
He pulled halfway out of her, dimly registering his brother were cheering on his efforts to knot the mule's ass now and slammed back it. The mule let out a long whining moan that was cut short as Spot thrust against the back of her throat, Rarity's anus stretched a quarter of the way around the knot she sounded almost disappointed when Fido's knot was forced back out.
Growling, Fido decided he'd had enough of her resistance. He gripped her flanks painfully hard, his jagged claws biting into her white skin and pulled back until only the tip of his tapered cock was between the lips of her anus. Glancing up at her Fido saw that Rarity was looking back at him with wide, scared, desperate eyes. The mule's anus clenched softly around the tip of his cock as if kissing it imploringly, searching for mercy even as Rover's knot was still battering against her cunt lips a few inches below. His eyes held Rarity's for several seconds letting her fear die down to smoldering ember before he thrust back in.
The mule's anus stretched a third of the way around him this time, but Fido refused to let her escape. He pulled Rarity's ass tight against his crotch, not caring how his brother's cock's pulled painfully against her mouth and cunt, and pushed himself forward forcing his knot in deeper. Rarity's cries became a crescendo as her pink pucker remained painfully stretched around Fido's knot, not allowed to retreat, and clenched painfully against her will around the big knot. The mule's squeezing felt so good that Fido almost lost focus and came. Instead, he steeled himself and pushed on, applying more pressure against his knot.
Slowly the mule's anus stretched a little further along his knot. Rarity cries continued even around her gags as Spot assaulted her throat. The agony was almost more than she could take, it dragged on second after second feeling like minutes and even hours before her anus finally crawled past the apex of Fido's knot. Once it had all it took was a single needy clench of her muscles and Rarity's mule ass swallowed the knot completely. She let out a long satisfied moan.
Rarity head swam, and she rested as Fido's brothers congratulated him. Her respite didn't last as Fido began humping into their mule again trying to get back to the edge of the climax he had denied himself. That spurred his brother on, and they began humping her with twice the vigor that had before. Rarity had to desperately gulp down breaths of air between gagging on Spot's cock. Rover knot crashed against Fido's bruising the already tender wall of flesh between them as Fido pulled his knot back painfully against her anus threatening to prolapse her ass with each frantic hump.
"We never going to give up whiny mule again!" Rover cried out raking another trio of scratches down Rarity's side. "Whiny Mule going to work hard every day!"
Rarity tried to cry out in protest, but it was drowned out as all three diamond dogs let out long howls and flooded each of their mule's respective holes with their watery cum. Rarity gulped Spot's cum down furiously to keep from drowning. But it more always came, the mule could feel Spot's balls against her chin frantically contracting with each spurt of cum. Rover held his knot tight against the mule's cunt not letting any escape. The pressure built until it forced its way past her cervix and filled her womb. Fido's cum had no chance of escaping past his massive knot and the mule's tight anus that clung to it feverishly. His cum washed deeper into Rarity's bowls; they cramped as the watery cum enema filled her completely.
Rarity's was sure her stomach was beginning to descend as it grew full of cum. But there was nothing a mule like her could do to stop the torrent of cum until her new masters chose to withdraw themselves from her now well-used holes.
