A/N: This is a fill for the 2014 Winter Kink Meme. The prompt is: How they deal with her period at different stages of their relationship.

It didn't take long for him to figure out why Beckett had been somewhat snippier and more frustrated than usual. After all, Castle had been surrounded by women his whole life so he was easily able to recognize the signs of when one was on her period. The thing is, he just didn't know how to approach the detective about it without getting himself shot.

So he kept her mug constantly filled with coffee and restrained the urge to spout off all of his normal crazy theories during their cases. He was just coming back from the bathroom when he spotted her hunched over at her desk, her hand running through her short hair before moving to her temples and lightly massaging them.

Without giving it a second thought, he walked by her desk, scooped up her empty mug and headed straight for the break room. He returned within minutes, a steaming cup of coffee held out to her.

Beckett glanced from the coffee up to his face and smiled softly. "Thank you," she murmured.

"Just let me know if there's anything else you need," he told her sincerely. He wasn't entirely sure if she had realized that he knew she was on her period, but he still wasn't brave enough to bring it up just yet. She'd only just forgiven him for digging into her mother's murder and he didn't want to give her another reason to yell at him. Any previous experience he'd had with this dictated that it was best not to bring up a woman's time of the month.

/-/-/-/-/-/-/-/-/

Castle knocked quietly on the door to Beckett's apartment and waited patiently for her to answer. He'd stopped at the precinct not too long ago and had been promptly told by Captain Gates that if Detective Beckett wasn't in her precinct, then he shouldn't be either. She'd apparently called in sick which, of course, had caused him to get a little over-concerned at first.

He'd been on his way to the nearest drug store in order to pick up any and all cold medication he could find when he'd realized what day it was. Beckett would be smack dab in the middle of her period so she probably called in sick because of that, not because she was actually inflicted with an illness.

Going to the drug store anyway, he'd bought Midol, a heating pad, and lots and lots of chocolate. That bowl of M&M's that sat on her desk always seemed to empty a whole lot faster around this time.

Hearing the shuffle of slippers on the other side of the door, Castle smiled gently when she opened it. If she wouldn't have slammed the door in his face, he would've laughed at how cute she looked in her sweats, a robe hanging loosely around her shoulders.

"Castle?" she scrunched her face up in confusion. "What're you doing here?"

"Don't hurt me, but I know it's your…time of the month and I wanted to bring you a few things to help you feel a little better." He showed her the plastic bag in his hand and said hopefully, "I was hoping that we could just relax and hang out and maybe watch some of those Temptation Lane DVDs that we never got to watch."

Yeah, they never got to watch them after that case several months ago, thanks to stupid Josh always calling and interrupting them. But now Josh was long gone and there was nothing to interrupt them this time.

"I didn't think you were that big a fan of it," she said.

"But you are," he replied. "So what do you say?"

She stared at him for a long minute before giving in and stepping aside so that he could enter through the doorway. "How did you know I was on my period?" she asked as she laid back on the couch while he set up her DVD player.

"I've known you for three and a half years, Beckett, and my mother never kept it a secret when she used to get hers. Add to that, the fact that I have a teenage daughter and I would have to consider myself an idiot if I wasn't able to read the signs and figure out when yours was."

"You are something else, Castle," she chuckled, rifling through the bag of chocolates he'd bought for her.

/-/-/-/-/-/-/-/-/

"Fuck," she cursed, placing a hand on her stomach and doubling over as a massive cramp hit her. Castle gazed at her helplessly from the other side of the couch. He didn't know how to make the pain ease up or go away completely.

Kate had popped a couple of Midol not too long ago, but it didn't seem to be working. Usually, she would feel some type of relief by now, but nothing was happening. When the medication failed, she'd tried a heating pad, turning it all the way up until she was sweating profusely. She'd received a little relief, but it wasn't enough.

Frankly, Castle just wanted to pull her to him and hold her until the pain stopped, every now and then planting kisses on her cheeks, her nose, her forehead, her lips to try to distract her.

"Jesus, Kate," he said, his hand reaching out to stroke up and down her arm. "I just wanna make you feel better."

She grimaced. "I know, Castle. But, unfortunately, I don't think there's anything that's gonna help me on this one."

Sighing, he tugged on her arm. "C'mere," he instructed, lying back against a couch pillow and guiding her to settle in between his legs. Her back lay against his chest as he enveloped her within the circle of his arms, his palms resting on her stomach. Brushing her hair over shoulder, he tucked his chin into the crook of her neck, his lips occasionally caressing the skin there while his fingers lightly massaged her abdomen.

God, he really did have magic fingers.

Almost instantly, she was able to relax and sit by while the sharp pain afflicting her ebbed away into a less noticeable dull ache—something that she was way more accustomed to than the horrible cramps she'd been stricken with this time around.

"God, Castle, how're you able to do that?" she wondered aloud. "How can you make me feel so much better with just a simple touch?"

"Because I love you." Honestly, that didn't really give her an actual answer, but then again she hadn't really been looking for one either. Who was she to question him and his amazingly gifted hands?

Castle never stopped the rhythmic motions of his fingers, dancing them over her stomach even as she drifted off to sleep.

/-/-/-/-/-/-/-/-/

Holy hell, he needed to stop. Right. Now.

They were decorating for Christmas now that Thanksgiving was over and it was just the two of them currently. Alexis was over at a friend's and Martha was at her acting studio and Kate didn't think she'd wanted her husband more than ever.

She could use the excuse that they were newlyweds, but that wasn't actually the reason. Her period had hit her hard this month and it wasn't with cramps or headaches or fatigue. She was fucking horny. It was rare for her to feel this way during her period, but when she did, it was almost unbearable. The sheer amount of restraint and willpower she'd had to exercise these past few days was unbelievable and she was at her wit's end.

And, of course, Castle had unknowingly worn one of the tightest t-shirts he owned today. His constant lifting of heavy, decoration-filled boxes was causing the large muscles in his arms to bulge and shift, half-hidden by the sleeves. Her resolve broke as he crossed each arm over his chest and stretched.

Walking over, she lunged for him, her palms pressed against his cheeks as she yanked his lips down to hers. Immediately, he responded, always eager to please his wife in whatever way possible. Her tongue forced its way into his mouth while she practically climbed up his body.

His shirt came off and then hers, quickly followed by her bra and he attacked her breasts, sucking a nipple into his mouth as he pinched and rolled the other between his fingers. Her hands wove through his hair as each nip and lick sent shockwaves coursing through her, each action heightened by the hormones that had been raging around inside of her for a few days now.

Castle's hand had just dipped under the waistband of her sweatpants when pulled back abruptly, his expression one of bewilderment.

"Wait, aren't you on your period right now?" he asked.

"Yes," she replied, desperately wanting to get back to what they were doing.

"Do you want—Are we gonna—?"

"Fuck?" she completed for him. "You're my husband, Castle. I'm okay with it if you're okay with it."

He appeared excited. "Hell yeah I'm okay with it! I just never wanted to ask you in case you thought I was weird or something like that."

"Castle, I will always think you're weird," she teased, her tongue poking out between her teeth playfully. "But now that we've cleared that up," she placed her hand on the bulge in his pants and squeezed, "Take me to the shower and fuck me so hard that I can't feel my legs afterwards."

His eyes darkened with arousal and within minutes, he had her naked and pressed up against the shower wall as he drove his cock into her. She really must've been horny as fuck because she was being louder than usual. Her normally soft moans had turned into throaty groans and though Kate rarely ever begged, her mouth just couldn't contain all her pleas and cries for more and harder and faster.

Castle glanced down at where they were joined and saw his cock covered in red, some of it running down his legs only to be washed away by the water. Instead of feeling repulsed or disgusted, he was actually more turned on and sharply thrust his hips, Kate shattering around him as she screamed his name over and over. He slammed into her three more times before he followed suit, spurting inside her until he had nothing more to give.

"Don't put me down just yet," she panted in his ear. "I don't think I could hold myself up."

"Mission accomplished," he said, laughing.

Huffing out a laugh along with him, Kate pressed her lips to the rapid pulse point on his neck and said, "Castle?"

"Hmm?"

"Thanks for having been there whenever I needed a little help during this time."

"Always," he promised.

A/N: I hope you like reading this. As of right now I have plans to fill more prompts from the Kink Meme so be sure to keep your eye out. Certain prompts I only put on my AO3 account so I actually have more kink meme stuff there than here if you would like to check it out. Thanks for reading!