Shar was having a very bad week. It had started with an arguement with Kacey of all people, an arguement that hurt Shar so deeply. They had planned a special date together, just the two of them, after Kacey's classes were out for the day. The tall golden labrador had dressed up as best she knew how, going through the painstaking process of picking out just the right outfit (in the end she needed Mabel's opinion before settling on a choice). She groomed her fur to near-immaculate perfection and showed up on time at their desired meeting spot, right under an artsy clocktower in the city square.
But Kacey never showed up.
Hours later after walking home in the rain, she found out from Mabel that Kacey had gone to a house party with her little clique. The hybrid realized her mistake far too late, however, and after making a mad dash for the meeting spot she quickly penned a lengthy apology via text to Shar. But the dejected canine was not herself by then, curled up nude after finally getting dry, weeping at the deep pain in her heart.
Over the next few days it hadn't gotten any better. Any responses Shar left on Kacey's phone were brief and devoid of the usual heart-shaped emoticons. both had grown distant over the course of a few days with little to no contact and Kacey dependant on her mothers and Cara for emotional support. Shar lacked such support herself until a day ago when things got even worse for the transgender canine.
She was in heat. Or a rut. Or both.
It had happened like clockwork every year since she started her transition but this year, when it seemed like Shar was over such intense hormonal attacks, it struck late and hard. Her erection wouldn't go down no matter how many times she stroked it. She was panting heavily and whimpering, desperately wanting to put her cock in someone. Mabel was away for the week for a long-haul client at the Farm, leaving Shar helpless and alone. The Clinic was the most reasonable solution, their Immediate Care wing could quickly grant her what she needed so badly. But that was where the 'heat' part of her situation came in. Shar desperately wanted to fill someone but at the same time he desperately wanted to be filled herself and could barely stand. The toys Mabel kept helped a little in that regard and offered Shar a little relief... but her nipples and cock still throbbed painfully with need, too much for her to even bear walking out the door.
"KKacey... oh, kacey..." she sobbed as she humped her bed, rubbing her cock and nipples on the sheet and moaning from the sensation, the thick plug in her tailhole on display. "I'm s-s-so sorry...! Aaahh!"
Shar spent a total of 24 hours in this state while the love of her life, still distraught over her actions, came up with what she hoped was the perfect apology. Kacey had been beating herself up all this time since missing the date. Word came down the grapevine from Nero that Shar had walked home sad and alone in the rain that night and the mental image the news conjured was too much to bear.
Now, she was determined to make amends and right her own personal wrongs. It was a holiday weekend and Kacey planned to spend ever minute of those 72 hours with her beloved, making up for the mistake and then some. It was rather simple at a glance: Kacey showed up Friday morning at Shar & Mabel's apartment dressed in a sexy version of her school uniform, made from a spare that Dio had held onto. A little creative shortening in places and Kacey looked like the ideal sexy schoolgirl complete with her own white collar in a little bag. Inside the bag was the matching leash along with some other uniforms she knew Shar would appreciate. To top it all off, Kacey had even done something she hadn't ever before: she used a potion to alter her gender and temporarily make her female. For the next day, kacey was a regular female willing to do anything to heal the divide and even felt a little thrill at experiencing life for one day as just a female and not a herm.
But when she knocked on the front door, there was no response. That threw Kacey for a loop. She knew from Mabel that Shar had the weekend off too and would be staying in for the day. SHe should have answered and just when all sorts of terrible posibilities came to mind, Kacey go the idea to try the handle. The door was unlocked and she walked in cautiously, shutting the door behind her. When the lock clicked kacey nearly jumped out of her skin at the sound she heard.
"Who... is it..." something growled in the dark apartment. Kacey's heart raced as she stuttered out a little squeak of a reply.
"I-It's me... Kacey," she spoke and started walking forward. There was a low huffing coming from the only bedroom in the apartment and she cautiously rounded the corner to stand and stare in the doorway. "Sh-Shar...?"
"Don't look!" the panting, huffing canine cried out. "D-Don't look at me!"
Shar looked awful. Her hair and fur were a mess like she hadn't brushed since yesterday and her bed was streaked with excessive amounts of precum drooling relentlessly from her throbbing black cock. For half a second Kacey wondered it it looked bigger than usual... then Shar pounced. The labrador was already incredibly tall and strong but she seemed even more so, leaping like a wild animal and pinning Kacey to the floor, both harms easily held by the thin wrists in just one of Shar's strong paws. Her eyes were wild and she sniffed the bunny/panda hybrid up and down, her nose even lifting the short skirt and sniffing at her bare pussy.
"N-Not kacey... no cock..." Shar growled and licked Kacey's entire crotch in one go, making the captive hybrid gasp and mewl in surprise. Shar's head shot up to lock eyes and for a moment, the real Shar was behind them, looking down with such intense love and devotion for Kacey. "K-Kacey... I'm s-so sorry... I-I'm in heat/rut... my c-cock hurts so much..."
"Sh-Shar? What can I do?"
The feral-like look started to creep back into her eyes and with much effort the labrador huffed, "P-Please... let me put it in..."
This wasn't what Kacey was ready for, at least not yet. She was expecting the first 24 hours together to mostly consist of extensive apologies, cuddling and then foreplay hence why she hadn't taken any contraceptive draught yet. This wasn't good, Kacey was unprotected and the way things were now, Shar might not be able to control herself. Kacey wasn't against geting pregnant, in fact she dreame daily about starting a family with Shar... but not yet. Luckily, there was a solution and Kacey was already formulating a plan.
"Let me s-suck it," she said quickly. "M-My muzzle will feel really good, really warm. P-Please?"
Luck was with kacey again and just enough of the rational Shar remained to enact the plan. It took much effort but Shar managed to stand upright, leaning heavily on the doorframe with her aching black cock twitching in front of Kacey. On her knees before her beloved, kacey did as promised and kissed the tip before lovingly sliding her lips down the shaft, more and more of the oddly longer-than-normal length disappearing into her muzzle. Shar let out a long, relived groan at the sensation of something warm and tight around her cock. Just as Kacey's lips touched the very swollen knot, she looked up just as Shar looked down, the two locking eyes.
That was enough to send Shar overboard. She moaned loudly as she came at long last, a blissful, intense wave of relief washing over her as what felt like gallons of cum poured into Kacey's stomach. Neither knew just when Shar's paws had reached up to hold her head in place but Kacey wouldn't have been able to pull off... not that she wanted to. She felt a tiny bump start to form as her stomach filled with Shar's hot seed and a joyful tear rolled down her cheek: the love was still there, stronger than ever.
But Shar's relief was short-lived as the desire started to quickly build again. This was her heat/rut, relentless for at least 72 hours but eased so long as someone was there to help satisfy the intense desires. Reluctantly, Shar released kacey's head and looked down at the hybrid, still with her muzzle and throat full of cock. "D-Don't stop... please," she begged, sounding more like herself for the time being. "You feel so good... i love you so much, kacey. <3"
That was what she had been waiting to hear. Soon the apartment was filled with the relieved moans and little huffs of pleasure from Shar and the eager sounds of Kacey's head bobbing. She had become so engrossed in pleasing her beloved she almost forgot the plan and moved quickly before losing herself. With an audible slurp she pulled off the throbbing black member and stroked it tenderly with one paw while the other reached into the bag.
"I wanna try something, <3" she said before placing something in her muzzle and again taking Shar's entirely length and pulling back again. Where there was once a solid black cock there was now a neon pink cock with a black knot at the base. With a little extra rubbing with her paws, Kacey eased the tight condom over the knot and admired the contraceptive now in place. 
"Th-That isn't one of those chastity condoms, is it?" Shar asked with more than a little worry on her brow.
"No, no, it's... s-something better," Kacey replied and stood up,taking Shar's paw in one of her own ad the bag in the other, leading back to the bed. "I-I wanted to do something special for you... f-for this weekend, I'm your pet. <3"
On went the collar and the leash clipped in place. Kacey dutifully offered the latter to Shar, blushing and smiling. Shar took it, blushing and smiling herself and pulled Kacey to her to kiss the hybrid passionately. When the kiss finally broke they stood there in each other's arms until Shar 's breathing became quick again and she huffed, "I c-can smell your pussy... you're soaking wet."
"All for you... M-Mistress. <3"
In a matter of seconds kacey was on the bed, squealing loudly with delight and intense pleasure as she was eaten out by Shar again, that canine tongue working wonders on her pussy. Shar's appetites were infinite, slurping greedily until she had forced out so many orgasms that Kacey couldn't even sit up. With her sex well and truly prepared, Shar scrambled into positio, again held Kacey's wrists down and looked deep into her eyes before ramming herself home in one go. kacey's back arched and she came again while Shar's tongeu lolled out at the rush of relief before she started moving her hips. No more foreplay, this was just fucking, pure and simple. Kacey's mind went blank from the intense pleasure as Shar fucked her for the first time in what felt like forever.
More than once Shar switched positions, angling Kacey like the little submissive she said she'd be. When Shar had kacey in a doggystyle position things reached a climax when, with a great, growling push Shar slammed her knot into Kacey's pussy. Neither realised that Shar had been pinning Kacey down beneath her breasts as they both came, one paw covering Kacey's muzzle and making the little hybrid cum even harder. The condom swelled as more and more of Shar's seed poured in, never breaking, just expanding in Kacey's womb and making a nice round bulge in her flat tummy. It worked perfectly, the super-elastic condom from Kei Corp keeping ever drop of Shar's cum contained as they both fainted from exhaustion.
When Shar awoke she was pleased to feel herself still knotted to kacey and wrapped her arms around her, hugging her tight. They stayed like that for a long time, cuddling and kissing and exchanging love-drenched apologies while both stroked the cum-ballon's bulge in kacey's stomach.
"I'd love to feel like this for real someday," Kacey said so softly after the sun had gone down. "Knotted to you... with our baby inside. <3"
Shar's heart skipped a beat. "Really? Y-You mean that?"
Kacey nodded. " Really. <3" There was quite a bit more kissing and cuddling before Kacey spoke again and asked, " How's you heat/rut?"
Shar blushed. "Still there, kinda... for another day at least. Um... do you happen to have any more of those super-elastic condoms in that bag?"
"And then some! <3"
Shar grinned and kissed Kacey between her ears. "Good... cause I wanna pour some more cum into your tailhole before I fill you like this again. And again."
Kacey giggled. "I love you."
"I love you too. <3"