Cat

Stiles knew that cats and dogs didn't get along. Honestly, he knew that. And he had known that when he agreed to this little cakewalk of a job but seriously, Derek's reaction was way over the top. The nostril-flaring and eye-glowing as he crept into the Stilinski house were 100% unnecessary and then backing away from the cat like it was a poisonous snake? That was just stupid. Derek was an Alpha werewolf for crying out loud, and Tilly was a six month old kitten. Stiles was pretty sure Derek would probably win that fight.

Besides, it would only last for two weeks while Stiles' neighbour was on holiday and then Tilly would be handed back, Stiles would be $50 richer and Derek could go back to not skirting around the edge of whatever room the cat was in. Everyone would be happy. Sure, Stiles would have to hoover the entire house to get rid of the fur, but he'd have $50.

That was the theory, the reason he had accepted, because getting paid for spending two weeks with an adorable bundle of fuzz hardly seemed like a job.

Theory.

It took Stiles right up until it jumped on the bed while him and Derek were making out to realise the cat was the Devil incarnate, because instead of Derek's half-naked, muscle bound frame on top of him he had a purring mass of fur kneading and nuzzling on his bare chest. He stared at her, nonplussed, as she yawned and stretched out, obviously getting ready for a loooooooong nap. Cockblocked by a cat. What even?

Derek jerked away to stand by the doorway, exuding jealousy.

"You're still my favourite," Stiles said to Derek, only half-joking. Derek was still insecure about their relationship even after six months. Insecure enough that he would probably think their cute lodger-kitten would come between them, which it definitely wouldn't because, seriously, mating bonds. They're pretty strong. Stiles nudged the kitten but she stared at him with huge, innocent, emerald green eyes. "Come on, off."

"I think she's comfy," Derek said sarcastically, crossing his arms and narrowing his eyes at the kitten.

"No, really, Derek?" He answered, ignoring the annoyed look he got in return. "I'd never have guessed. With all my investigative instincts I never realised that she might be comfy. Thanks for sharing, the purring had me confused."

Derek grabbed his shirt and stalked out of the room.

"See what you did?" He said to Tilly, who ignored him and buried her nose in her tail. He scratched her behind her ear. "You're officially a home-wrecker."

...

It was two days later when he first saw Tilly as a threat to his wellbeing. Sure, interrupting Stiles' sexy time with Derek had been seriously annoying and attacking the loose thread on Erica's jacket had resulted in a major wolf-tantrum complete with foot-stomping and growling, but he didn't take the wolves' complaints seriously until he was on the receiving end on Tilly's claws.

She didn't do it on purpose. Stiles maintained that viewpoint even while Derek was cleaning the wounds on his arm meticulously with antiseptic. She was only playing. He had been dragging a catnip mouse across the floor in the living room (watched disdainfully by Derek, who muttered that a predator shouldn't be so easily fooled) and Tilly had pounced on the objects that smelled like cat drugs, Stiles' hand included. Cue blood, a snarling Derek and a frightened kitten that ran to hide behind the sofa, mewling pitifully.

"You scared her," Stiles said when Derek was clearing away the first aid kit. "You're going to be renowned for terrifying small animals."

"She attacked my mate. She's lucky to be alive," Derek replied, matter of fact, like threatening a tiny kitten's life was standard behaviour.

"Okay, that kind of wolfy shit might make sense to you, but she's a kitten, not a wolf," he walked over and rested his head against Derek's shoulder, tangling their fingers together. "I like it when you call me your mate." He looked up just in time to see Derek's eyes flash from red back to green and then darken as the pupils expanded. "I like it a lot," he whispered, millimetres from Derek's lips, before kissing him slowly and thoroughly, sliding their tongues together and pulling away all too soon. "I could shut her in the living room? Dad won't be home until later..."

"That," Derek replied, taking his hand off Stiles' neck, "Sounds like a good plan."

...

"Derek?" Stiles murmured into the darkness. He got no reply, even though he could feel Derek's broad, muscled chest behind him. The menu of the film they had been watching was playing on a loop, epic music turned right down in the background. Apart from the light from the screen, the room was completely dark. Movement on his legs told him that Tilly was curled up, sleeping on his lap like she normally does in the evenings. He took a moment to stroke her silky white fur before plucking her off and setting her on the couch next to him, then standing up himself and stumbling through to the bathroom.

While Stiles was washing his hands, he heard a disgusted noise coming from the living room, followed by a slightly hysterical call of his name. He ran through the kitchen into the lounge, like, Usain Bolt would be proud of the speed he travelled.

"She scent-marked me!"

Stiles couldn't even stay on his feet he was laughing so much. He crumpled onto the armchair nearest to him and laughed so hard he wept because strong, tough Derek 'I'm the Alpha' Hale was looking at the kitten leaning on his chest with outright revulsion. He looked so confused that Stiles just wanted to hug him. It was adorable. Instead, he whipped his phone out and snapped a picture, forwarding it to the entire pack before Derek realised what he was doing.

Only then did he walk over and lift Tilly easily off of him, cradling her gently in his arms.

"Isn't she a cutie? She accepted you, that's what scent-marking is, don't worry," Stiles said, running his fingers softly through her belly-fur until she was purring happily again. Derek continued to watch them grumpily until Tilly wriggled free and went in search of food. Stiles flopped back down, half sat on Derek. "I love you. You know that, don't you?" It was a rare moment of clarity. Derek needed reminding every now and then and, like always, his eyes softened and he kissed Stiles' forehead.

"I love you, too," Derek responded, "But tell me there isn't long left."

"Another week. We've reached the halfway point." Stiles laughed at the despairing look on Derek's face.

...

Stiles got home from delivering his dad's lunch to find Derek's Camaro parked at the side of the road with no one in it. From that, it was a pretty safe guess that Derek was inside somewhere, either using the key Stiles gave him or taking his preferred route through the window. Honestly, someone needed to teach werewolves some manners. He unlocked the front door and called out a greeting. There was no answer apart from a weird burst of movement from the living room. Stiles walked through frowning.

Derek was sat awkwardly on the sofa closest to the TV, some weird cooking programme that he liked for some reason on the screen. The Alpha was making a valiant, but no less obvious attempt at avoiding Stiles' gaze. That made Stiles frown even more until he walked around the sofa and saw Tilly on the floor, stood awkwardly with her fur ruffled and stuck up at odd angles. Her eyes looked bleary... Almost like she'd just woken up...

Stiles felt Derek's kitten-warm legs and then gave him an unimpressed look.

"Did you throw her off just because you didn't want me to see that you like her?" He asked, raising his eyebrows when Derek stuttered and tried to deny it. Stiles picked Tilly off the floor and held her out to Derek, who took her without a word and set her back on his lap, smoothing down her fur. "It's nice to see you've accepted her to the pack."

"More like she's accepted me," Derek muttered bitterly, belied by the fact he was looking at her with something akin to tenderness in his eyes. Stiles sat down next and tucked his feet under himself, leaning heavily against Derek.

"Thank you," Stiles said, kissing the patch of skin just below Derek's ear.

"What for?" Derek asked, nuzzling into Stiles, who bared his neck shamelessly.

"For not being your usual douchey self to her, even if it took you a while to come round."

"I think there's a compliment in there somewhere," Derek said, kissing the moles on his throat almost reverently. "And you're welcome. But if she hurts you..."

"Aww. Willing to protect me from vicious kitty claws?" Stiles teased before dropping a kiss on Derek's frowning mouth. "You're such a superhero."