Based on a prompt from castlefanficprompts on tumblr: "First time Beckett calls Castle babe :)"
Set anytime between 'Probable Cause' (5x05) and 'Still' (5x21/22). Enjoy, and happy Castle Monday!
Castle restlessly shifted his legs once more as he wriggled on the leather couch, gently grasping at the laptop screen to ensure that it didn't drop and break on the living room floor, making him lose the current draft for the third chapter of 'Driving Heat'.
Not that there was much to lose anyway.
He'd always known that he couldn't write as effectively when he wasn't in his office, needing a combination of the comfort of his chair, the warm glow of the lights that basked behind him, and the photos of his loved ones placed on his desk.
But it was thanks to one of the said loved ones that he was temporarily banned from his office.
He'd been sharing the desk with Kate after she'd dragged a chair from the dining area, both of them comfortably sat with their laptops, him writing fiction and her writing case notes for an upcoming court hearing.
When he paused after concluding a car chase scene, he timidly looked over to his girlfriend, taking in her features. The messy bun that was tied to the nape of her neck, the purple sweater sleeves that covered the majority of her hands flitting over the keyboard, her pearly white teeth biting down onto her bottom lip as she leaned forward slightly to read some smaller print.
She looked… comfortable.
At home.
The thought made him intake a sharp breath, which Kate didn't register as she rapidly clicked over a series of web page tabs. Though he'd always had the niggling feeling in the back of his brain that a relationship between him and the Detective was inevitable since the inviting tone of 'Mr Castle?' made him spin on his heels at his book party, he couldn't help but feel incredibly blessed that they'd made it after everything they'd been through together.
From gun battles using champagne bottles, to exploding apartments, to almost becoming tiger kibble, they'd fought through a lot to be together.
And it was definitely worth it all.
This train of thought led to an irresistible urge for Rick to kiss his partner (which was usually present anyway), so he leaned forward and placed a gentle kiss on her jaw, chuckling as she jumped in her chair, before leaning into his touch, though even without looking he could tell her gaze never wandered from the pixels in front of her.
Huffing quietly at her lack of response, Castle brought his lips to the pale column of her neck, gently nipping with his teeth until he heard a small groan emit from her throat.
Once he looked up, he realised it was a groan of annoyance.
And so, with an arched eyebrow and a fold of her arms, he was banished from the space. Not without an appropriate amount of whining though, making Kate's lips turn upwards slightly as her right hand continued to shoo him.
After about thirty minutes, she walked out of the office with her nimble fingers tangled in her chestnut locks, attempting to brush out the kinks in the curls as she spoke.
"Babe, do you have a scanner in here?"
Castle snapped his head upwards at her, his head tilting slightly at her words.
"I need to scan some papers to email to the other officers. It'll be easier than giving out copies at the precinct."
She pursed her lips in confusion as her lover remained silent, but continued anyway.
"If you don't have one, I'll pop back to my place. And I'll be back for dinner if you want?" She proposed, her voice lilting upwards near the end.
"You babe'd me."
Kate's eyebrows scrunched together at the reply she got, but definitely wasn't expecting, "I what?"
"Babe'd me." He repeated in a clear tone, as a large grin appeared over his features.
Her gaze fell to the right as she backtracked through the conversation. Once she realised, her mouth opened and closed multiple times, much to Rick's amusement.
"So?" She finally piped up, acting nonchalantly about the teasing she was no doubt about to receive.
"Nothing," Castle shrugged, still with a smile plastered on, "I just didn't think you were a babe person."
Kate squinted her eyes at him, "Well if you're not okay with babe, I could go with kitten." She replied, pressing her lips together in an attempt not to giggle at the miniscule shudder that crept up Rick's spine at the mention of his former pet name.
"You wouldn't." He dared in a low voice, attempting to appear menacing, but knowing he had failed.
"Oh, but I would." Kate playfully retorted back in a similar husky tone, raising her eyebrows as she waited for his response.
He sighed with a pout, "Scanner's included in the printer, just lift the top lid up," He resigned, making his girlfriend chuckle as she walked out back into his office, content with her victory. "Honeybun." He added shortly after, the frown falling off his face once he heard Beckett's lighthearted scoff.
"Thanks, stud-muffin!" She shouted back through the book shelf wall with a teasing undertone wrapping around the syllables.
He was suddenly very grateful that they were alone in the loft. If his Mother and Alexis had teased him about 'kitten', they would have a field day with this information.
The following morning, Kate glanced up from her desk at the precinct when a body-shaped shadow was cast over her, finding Castle standing with glimmering blue eyes and a too polite smile on his face. Wordlessly, she grins back at him, reaching her right arm forward so she can take his sweet treats from his grasp; her coffee cup and…
"A muffin?" She asked, wondering what prompted the change in his usual order.
He perched down onto his chair slowly, his teasing eyes never leaving her curious ones as he explained his reasoning.
"Yeah," He agreed with a firm nod, "Y'know, a muffin from your stud. Since I'm your stud-muffin and all."
Beckett spit out the first sip of her sweet drink, immediately pressing her hand over her mouth as Rick's loud guffaw bounced off the surrounding precinct walls, followed by twin disgusted groans from Ryan and Esposito, who no doubt heard Castle's teasing.
However, in the haste of cleaning up her coffee mess (which somehow made it all the way to the elephants) and slapping her partner's hands away as he gently stroked them on her arms in an attempt at an apology, she doesn't spot Gates' smile from through the Captain's office window, shaking her head at the Detective and the civilian's antics before getting back to work, trying not to focus on their hushed whispers.
If only they knew how badly their little secret was being kept.