Cassette had settled easily into their new life with Dove and Sunny. The college-aged cheetah only took a few weeks to fully move in with the older cat and his pet husky-spaniel mix. There was no written contract between Dove and Cass. The rules were simple and unspoken. The cheetah could be used by Dove or his dog at any time, using any hole. It was an irresistable offer for the obsessively horny cheetah. 

On their first night there, Dove popped some champagne bottles and made Cass masturbate in front of him. Cass undressed nervously at first, but after undressing glanced towards Sunny in his crate, then looked to Dove with a pleading expression. They didn't even attempt to masturbate, and were already soaked from anticipation.
"Poor thing," he'd told them as he fetched Sunny from the crate. "You're not gonna be able to cum unless you're getting bred by [i]something[/i], huh?" Cass had nodded, pouting slightly. 
"That's perfect for us then," he'd said, grabbing the cheetah by the scruff and bending them over the couch. Cass didn't resist him. They didn't want to. Especially not when they felt a warm dog tongue between their legs. Cassette barely needed any training from Dove. They were so desperate for it they eagerly spread their legs when the husky mix mounted them. All Dove had to do was praise them for being so easy as he helped guide Sunny's prodding dogcock to the cheetah's dripping pussy. 
"You just [i]need[/i] that fuckin knot, huh?" Dove asked as Sunny's hips lunged against Cass.
"Y-yes," Cassette gasped, gripping the couch tightly. "Mmf.." Dove stepped back and pulled out his phone, beginning to record the breeding session. Cass hid their face by burying it into the couch, but their distinct striped tail would be even easier to spot them by. Sunny eagerly bred the cheetah, panting and huffing as he took out his pent up energy out on them, the room quickly filling with sounds of Sunny aggressively fucking his new cocksleeve and Cass's loud mewls and moans. 
"Don't hide it babe," Dove said, holding his phone with one hand and stroking himself slowly with the other. "Say it. Tell me what you love."
"I-" Cass groaned, shuddering as they breathed through clenched teeth. "I love. I love being a dogslut. I love getting bred. I fucking [i]need[/i] it."
"Yeah you do," Dove purred. "Go ahead and cum, slut." Dove couldn't help but grin as Cass came with shuddering, desperate gasps. They sounded like they were drowning, barely able to come up for air. Dove decided to take advantage of their open mouth and knelt on the couch in front of them, grabbing them by the ear and shoving his cock into their open mouth. Dove grunted as he felt their sandpapery tongue slide against his cock, but managed to not shake the camera too much - he wanted to make sure he got a good video of Cass taking dick in case the cheetah ever changed their mind. Was a little late for that. 

Sunny huffed as his hips froze against Cass. 
"That's it, boy," Dove murmured. "Knot 'em good." Sunny laid panting over Cass's back for a moment before slowly sliding off. His knot was nice and deep in the cheetah's pussy, tying them in place, butts pressed together. Cass started to gag on Dove's cock, but Dove just ignored it and focused on getting a good overhead shot of their tie. 
"Stop whining," Dove muttered to Cass, sinking his cock even further down their throat. Trapped between them, Cass had no option but to take it, making fun gulping noises that massaged his cock. He kept his camera steady, grabbing Cass's tail by the base to show off the tie a bit better. [i]Nice and snug[/i], he thought to himself. The knot visibly flexed and tugged against their pussy before finally slipping out with a gush of cum. Cassette's thighs trembled as it slid out. Dove ended the recording, then finally pulled his cock out of Cassette's throat so they could breathe.
"Welcome home, kitty," Dove said. Cassette drooled onto the couch and weakly smiled, managing a soft purr after coughing a bit. Dove grasped their cheek (gently, this time) and stroked himself off, cumming with a sof grunt. He coated the cheetah's muzzle and cheek and admired his seed dripping down their face. [i]Yep[/i], he thought, looking down at their blissed out, stupified expression. [i]This one's a keeper.[/i]

Dove would happily introduce the younger blushing cheetah as his girlfriend or boyfriend - whatever suited him at the time, but was always met with uncomfortable looks due to the pair's age difference. Dove was old enough to be Cass's father and then some. And Dove was [i]extremely[/i] into that. He got hard any time someone commented on it, sometimes letting Cass know with a sidelong glance. He seemed to enjoy making the cheetah feel awkwardly turned on, especially in public. And on one particular trip to the mall, about a week after Cass had settled in, Dove decided to turn that up a notch.

The mall trip started as a little treat for Cass to pick out some new clothes - nice clothes - because the cheetah had been wearing thrifted outfits and hand-me-downs for as long as Dove had known them. He wanted his pets to look good, he figured. Nothing wrong with that. They started with some cute new tops. Dove couldn't really hide the fact he loved crop tops on [i]his[/i] cheetah. Their soft, kissable belly being exposed like that was a good look. Cass was a little shy about that much being revealed so they picked a light jacket and jeans to go with it. While they were trying on jeans, Dove absently thought about how Cass had blushed when he'd introduced them to his drinking buddies as "the new pet". He smirked.
"Dove?" Cass's voice snapped him out of it. 
"Yeah?" he glanced over to the fitting room, where Cass was peeking their head out. 
"Can you help me with something?" 

Dove closed the fitting room door behind them. The room was small and cramped, with a bench to sit on and a mirror across from that. Dove sat down on the bench while Cass showed him two different pairs of pants. Cass wasn't wearing any themselves, just their panties - the "tomboy" kind that looked kinda like briefs but more close-cut. Dove's eyes drifted to their inner thigh.
"So this one I think looks a little cuter," Cass said, unaware of the thoughts brewing in Dove's head. "But this one-" Dove reached out, sliding his hand over Cass's thigh. Cass instantly blushed and seemed to lose their train of thought. 
"Sit on my lap," Dove said.
"B-but-,"
"That's an order. Facing the mirror. That's it."

Cass settled slowly into Dove's lap, nervously trying to not make eye contact with themselves in the mirror. Dove grasped their thighs and lifted their legs, spreading them. Even with panties on, the outline of Cass's soft pussy was visible. 
"I don't think we should-" Cass attempted to protest, but Dove was already tugging their panties down and over their feet. Cass started to protest a little louder when he pulled out his cock, but Dove wasn't having it. He shoved Cass's panties into their muzzle, softly growling in their ear. 
"Don't make too much noise," he said. "Just relax and take it." He didn't wait for a response, spreading the cheetah's pink pussy and sliding his cock in with surprising ease. Seemed like the cheetah just got wet any time he needed. [i]Definitely got lucky with this bitch,[/i] Dove thought to himself as he started to breed his pet. 
"Look," he muttered against their ear, nodding to the mirror. The reflection showed in perfect detail how much his cock stretched them out and how deep it was sinking in. Cass made a muffled whimpery noise. He started going faster. Cass bounced up and down on his lap with soft slapping noises. Cass started to get a lot more flustered. They were visibly flushed through their soft white and yellow fur and making adorable muffled noises through the panties shoved in their maw.

As the friction increased and Dove started to breathe harder, he switched to slower, deeper thrusts. As his breathed raggedly and the two of them started to drip sweat, there was a sharp knock on the door. Dove instantly covered Cassette's already muffled muzzled and hoarsely asked "Yeah?" Cassette's eyes rolled back a bit as the full length of Dove's cock sank in, balls deep. There was a pause.
"Sorry," the person on the other side said. "Just checking if there was someone in here." As they shuffled away, Dove exhaled slowly against the back of Cass's neck. 
"Hey sweetheart," he said, voice barely above a whisper. "Feel that twitch? I'm gonna fill you up." Cass nodded frantically, the panties finally sliding from their mouth just as Dove growled against their neck and sank his teeth into their scruff. 
"Daddy," Cass gasped. Dove instantly stiffened, his cock flexing so hard when he came that he could see Cass's tummy bulge in the mirror. He groaned into the bite, his balls tensing as he filled Cass up. They made a little noise - a soft "ah!" that Dove couldn't help but think was adorable. Cass looked so good getting bred from his view, he couldn't help but release their scruff to immediately cover their neck and shoudlers in kisses.
"You're such a good little pet," Dove purred to Cass. "Look at you, calling me daddy without me even asking." Cass was panting softly, sweat dripping down their thighs. His cock flexed and twitched inside them. 
"Did anyone hear?" Cass asked through their hazy expression. 
"Fuckin' hope so," Dove muttered. He watched the reflection of the two of them until his cock slowly slipped out. Cum drooled from their well-bred hole. Cass was watching themselves in the mirror too, seemingly entranced by the sight.
"W-we should..." Cass's voice trailed off. 
"Hm?" he asked. He could hear people coughing and shuffling hangers around just outside the door.
"We should get a mirror. In my bedroom," Cass muttered.
"Yeah," he agreed with a grin.

The two lived in a haze for several weeks - Dove worked, came home, and it wasn't uncommon to find Cass either begging for him the instant he walked in - or taking matters into their own hands and being tied with Sunny. But it wasn't until nearly a month in that he noticed Cass had a bit of a glow - something he couldn't quite put his finger on, but they were different. He found himself being more gentle with Cass even when they begged for it rough. Perhaps he shouldn't have been surprised when he finally walked in one day and saw Cass sitting on the couch, lost in thought.
"Babe?" he asked. They looked up.
"I'm pregnant," Cassette said, their expression shifting like they felt somehow guilty. But Dove threw his work things down, ran to Cass, and hugged them tightly. 
"You have no idea," he said, "how fucking happy that makes me." Cass started to cry, and Dove only held them tighter, licking and kissing all over his pet. 
"I thought you'd be mad," Cass whimpered.
"[i]Cass[/i]," he said, "sweetheart...why the fuck else would I be breeding you every fuckin' chance I get?" Cass hugged him back, tightly. 
"Just promise Daddy," Cass said, "you'll keep trying to get me pregnant even if I'm already-"
"You know I will," he said, stroking Cass's cheek. Then, slightly lower, he growled. "You [i]know[/i] I will." Cass purred, and the two sank into each other as Sunny ran over and jumped in to join the cuddle puddle. The odd throuple had never been happier.