I didn't get as many reviews on the last chapter, or as many hits, but I'm going to assume the day was down has something to do with that.

This chapter is going to start during the actual weekend of Memorial Day. It's the first time Kate has been around Martha and Alexis since she and Castle started a relationship…or admitted to having a relationship because they kind of had one before even admitting to it…in a complicated way, lol.

I still don't own Castle…

xxxxx

Kate sat curled on the couch in the living room Friday evening after dinner, reading a book with a glass of wine. She had opted to read in the living room instead of Castle's office where he was writing, or more accurately typing. After the girl's night she'd had with Lanie the previous weekend and her friend's suggestion about Castle's fingers, she found herself unable to focus on anything other than where she wanted them on her body; considering he still wasn't allowed physical activity, she needed to avoid those thoughts, and she couldn't do that if they were in the same room while he was typing. Besides, Alexis and Martha were both there, and she didn't feel comfortable hiding away with Castle in his office when there were other people in the house that she should and could be sociable with…or at least not seem antisocial with.

Alexis spotted her in the living room on her way to the kitchen for a bottle of water and approached her. "Detective Beckett?" she interrupted her reading softly.

Seeing the redhead standing near the couch, Kate gave her a smile. "You can call me Kate," she told her again. "If you need your dad, he's in his office."

"Actually…I wanted to talk to you, Kate," Alexis told her.

Kate marked her spot in the book and closed it, placing it on the coffee table in front of her beside her nearly empty wine glass and gave the young woman her full attention.

Alexis took a seat in the cozy armchair by the couch. "Dad told me about you two…" she started.

She could feel her stomach tighten slightly from nerves at the direction this conversation was heading. The irony was not lost on her–she could go toe to toe with the toughest criminals in NYC, but she was nervous having a conversation with Castle's 17-year-old daughter. She didn't say anything, though, waiting for the girl to go ahead with the conversation.

"I know my dad isn't usually a serious person…but I just wanted you to know how serious this is for him," she continued.

Kate's eyes softened in realization. Alexis was going to give her the don't hurt my dad talk. "I understand your concern. It's serious for me too, Alexis."

"Is it? Because Dad doesn't do this…" she gestured to the room. "Dad doesn't bring girlfriends home unless it's serious…really serious. The only time I met someone he was dating was with Gina…and he married her. So being here…me knowing…Kate, you need to know what that means. Because I've seen how much he cares about you; I've seen how hurt he has been at times when you guys were fighting, or a couple of summers ago when you kicked him out…" she trailed off. Though she didn't completely know why her father hadn't been back after that first summer, she just knew he had been upset, and even more so when the detective hadn't immediately taken him back, and he really thought they were done.

"I know my dad is immature a lot of the time, but he has a big heart. He loves big, but when someone he loves breaks his big heart…" she met Kate's eyes, "Gram and I are the ones left to pick up the pieces." She was quiet for a moment to let her words sink in. "I need to know that you're not going to hurt him. I'm not sure we'd be able to put him back together this time."

Kate remained silent, trying to sort out what exactly to say and how to respond to his daughter. "Alexis…" she started softly. "I care about your dad…so much. But I can't promise you I'm never going to hurt him. Sometimes we hurt people we care about without meaning to, and when that happens, hopefully, the relationship is strong enough to withstand it. What I can promise you, is that I will never intentionally hurt him. I will never intentionally break his heart," she decided to just talk to her like an adult and hit her with the truth.

"This relationship with your dad…Alexis, it's the most serious relationship I've ever been in. He's my best friend, he's my partner; one of the reasons it's taken us so long to get to this point together is because I was afraid of losing that," she continued to explain, wanting the young woman to understand how much Castle meant to her, how important he was to her. "This isn't a fling, or some kind of casual relationship to me. I told him, and you deserve to know this too…I'm all in. No games, no running," she promised.

The redhead sat quietly, studying the other woman, digesting her words. "In that case…I'm really glad you're here. It will be nice to have another sane person around," she finally smiled, accepting her words as proof that her dad was safe with Kate and moving from her chair to surprise her with a hug.

Kate finally released a nervous breath she hadn't even realized she'd been holding as Alexis seemingly accepted her. "I know you've always been friendly, but I really would like to be friends."

"I'd like that too," Alexis told her with a smile. "Actually…I thought I might ask you something else. Dad said you brought your motorcycle…"

"Are you interested in bikes?" Kate asked with a smile. She hadn't really pictured Alexis as the type, but then again, she didn't really know the girl; she only knew what Castle had said about her. She knew Alexis had asked for a scooter…so it wasn't such a big step up from that to a motorcycle.

"I think I might be interested. And I know cute boys are intrigued by girls who like bikes," she grinned.

"They are indeed," Kate laughed softly. "If your dad is okay with it, I'll take you out for a ride so you can decide if you like it without the influence of cute boys."

"I'd like that. And I know he'll say yes," Alexis smiled

xxxxx

As Alexis had predicted, Castle had been agreeable to Kate taking her out for a ride on her motorcycle. He actually felt safer with Alexis riding with Kate than if his daughter just hopped on the back of some random boy's bike. He trusted Kate implicitly; teenagers driving motorcycles, not so much. When the two got back from their ride, he opened the door in time to see Kate remove her helmet and shake out her hair before Alexis gave her a hug and handed back the extra helmet to her. "Have fun, Pumpkin?"

"Dad! It was so much fun!" Alexis gushed as she rushed toward the house and gave him an excited hug. "Kate said she can teach me to ride one if you say it's ok. I know there's no one else you'd rather show me how to ride because I know how much you trust her. And she's a cop, so you know she's going to tell me how to be safe, and you know I'm already super cautious. So is it? Okay?" she looked up at her dad hopefully.

Castle couldn't help but chuckle at her enthusiasm. "Okay," he laughed. "You're right, if you're going to learn, I feel much better with Kate teaching you than anyone else. So if she's fine with that, then sure."

"Thanks Dad!" she gave him a big hug before running past him into the house.

"Where are you going?"

Alexis slowed down enough to turn back to her dad with a smile. "I have to go read about the controls and the safety rules and everything about how to ride!"

Castle laughed again at his daughter's excitement before heading out of the house and to the driveway where Kate was leaning against her bike slightly. "I don't know whether to be horrified or impressed with how you have seemingly turned my daughter into a biker," he commented with a smile.

Kate rolled her eyes. "She's hardly a biker, Castle," she smiled. "Besides, if you haven't corrupted her in 17 years, I highly doubt me teaching her how to ride a motorcycle is going to be the linchpin in her corruption."

"Fair point," he nodded. "So she got a ride on your bike…when do I get one?"

She studied him for a moment. "You're jealous you didn't get the first ride, aren't you?" she tugged her lower lip between her teeth.

He shrugged. "No. It's fine. I'm just wearing this leather jacket because I think it looks cool."

Laughing, she tossed him the extra helmet. "If you wanted to ride before her, you should have just asked me."

He grinned excitedly, waiting for her to get on the bike again before he slid in behind her. "I'm not even disappointed you aren't wearing your leather pants."

She shook her head, rolling her eyes again. "I usually just ride in jeans. I only wore leather for your benefit when I rode in."

"Well, whatever the reason, I appreciated it. You look good in leather," he grinned.

"Maybe I'll wear them next time," she smirked. "Have you ever ridden on the back of a bike before?" she asked him. Seeing him shake his head no, she nodded. "Ok, hold on tight to me. You need to be close to me to feel my body language so you can mimic it. If I lean, lean the same way, ok?"

"Close isn't going to be a problem, Kate," he chuckled.

"Rick, I'm serious. You have to mimic my movements, so you have to pay attention to something other than the fact you're pressed against me," she stressed to him. "Don't lean more than I do, or you're going to throw us off balance, and it will be a bad day for both of us. Don't be too stiff, or you will mess with my control of the bike. So relax and move with me…you, me, and the bike are one, got it?"

He nodded. "You, me, and the bike are one. Got it. What else?"

"Find a comfortable spot to sit in and try not to wiggle too much…again, you'll throw off my balance. I'm not going to be able to hear you through our helmets and the engine, so if you need to stop, tap my thigh and I'll pull over, ok? Beyond that, don't distract me. Think you can manage that?"

He nodded again. "Don't wiggle. Tap your thigh if I need to stop. Don't distract you. Got it."

"Okay," she smiled, shaking her hair back out so she could get her helmet on. Once he had his helmet on, she started the bike. When he put his hands on her waist and leaned close to her, she grinned and took his hands, giving him a gentle tug closer so that his arms were wrapped around her and he was pretty intimately pressed against her back. She gave him a moment to get comfortable before easing her bike down the driveway and out onto the road.

The ride she took with Castle was much longer than the one she'd given Alexis. She'd wanted to give Alexis a little taste to see if she enjoyed it, but Castle's ride was about just being free with him, having him close to her. They spent much more time on the highway than she had with Alexis.

Once they finally returned to his house, she drove her bike into the garage to park it, killing the engine once she had her kickstand down. When he moved to get off, she stopped him with her hand on his thigh and a shake of her head. Once their helmets were off, she placed hers on the ground and gestured for him to do the same before swinging her legs around carefully so that she had turned to face him on the bike. She gave his leather jacket a tug so that slid closer to her, her legs draped over his thighs so that she was almost in his lap. "Enjoy your ride?" she asked with a smile.

"Very much so," he nodded, his hands moving along her thighs to her waist. "But now I'm wondering if maybe it's not over yet?"

She grinned a little more, biting her lower lip before closing the distance between them with a deep kiss. She unzipped his jacket so that she could use the opening to grip it and hold him closer.

"Kate…" he groaned lowly, finally pulling back from her kiss. "I thought you said Lanie told you we had to wait until I got the go-ahead from my doctor?"

"Actually, she said not to get your heart rate up too high until you get the all-clear from your doctor," she murmured with a smile, moving closer again. "I'm not trying to have sex with you," she kissed him slowly again. "I just want to make out with my boyfriend a little…" she practically purred in his ear with a smile. "If you think your heart rate can handle it, that is," she arched an eyebrow, pulling back slightly so he could decide.

He honestly had no idea if his heart rate could handle making out with Kate Beckett on the back of her Harley, but there was no way in hell he was turning down this opportunity. He answered by using his hands on her hips to pull her close again, watching her eyes dance playfully for a moment before kissing her slowly, his tongue sliding along hers sensually.

A low moan escaped her throat, one hand moving to thread through his hair as she deepened the kiss. Her free hand moved to his shoulder, using the leverage to raise up enough to slide closer until she was completely straddling him as she pressed her hips against his. She was playing with fire, and she knew it, but she didn't care at that particular moment. She was amped up from her bike ride with him, and damn it, she wanted him. Responsible Kate had taken a backseat to a sexually frustrated Kate mixed with a re-emergence of Rebel Bex, which could prove to be a lethal combination.

Feeling her completely pressed against him caused him to groan again, and his lips moved from her lips to her neck. He unzipped her leather jacket, moving his hands inside and to the soft skin of her sides underneath her t-shirt. When her head fell back to give him better access, he grinned against her throat, his teeth and tongue grazing lightly along her skin.

His mouth returned to hers, and she took control of the kiss, her tongue tangling with his as she immediately deepened the kiss. With a low, seductive moan, her hips rolled against his in a deliciously slow rhythm before her lips moved along his jaw to his neck. She gave his pulse point a playful bite before soothing the spot with her tongue and sucking gently, her hands moving inside his jacket to slide up his back.

"Shit…Kate…" he groaned, his fingers digging into her hips as she rolled them against his. He decided then if he didn't survive this, at least it would be worth it. One hand slid up her left side slowly, moving to cup her breast through her bra. The way she moaned so erotically and pressed her chest into his hand drove him crazy.

Her eyes met his, and each could see the passion, the desire, the lust there. Her mouth covered his again, her tongue just finding his when the door leading from the garage into the house slammed, signaling they were not alone. Kate instantly dropped her forehead to his shoulder breathlessly.

"Alexis thought she heard you come back," Martha entered the garage casually. Seeing their current position, she grinned. "I just came out to tell you dinner is ready. But I see you two lovebirds started with dessert."

Castle swallowed hard and had to force his breathing to even out. "Thank you, Mother. We'll be right in."

"Oh, take your time, dear. Alexis and I can wait until you've finished," Martha waved them off. "Carry on," she added, heading back into the house.

Castle waited until he heard the door slam again to signal his mother was safely back inside before removing his hands from underneath Kate's shirt. "I'm sorry…I swear, my mother lives for moments like that…I'm really sorry…" he apologized.

Kate raised her head from his shoulder, and she couldn't help but laugh.

Shaking his head, he studied her, not understanding what was so funny. "Why are you laughing?" he finally asked, relieved she wasn't upset.

"I'm sorry, it's just…it's been a really long time since I got busted by a parent making out with a guy on the back of a bike," she laughed.

Her laughter made him smile slightly. "Yeah?"

"I was a teenager and my dad was the one who caught us," she managed to control her laughter enough to talk. "I had snuck out of my room for a date," she started, a few giggles escaping.

"Oh, and your dad caught you sneaking out?"

She shook her head. "Sneaking back in. At 5 AM when he stepped outside to get the paper," she grinned.

His eyes widened. "Oh…"

"Yeah," she laughed again. "I had been out with this guy all night. I thought my dad was going to have a stroke." Her smile faltered slightly then. "I don't know how she did it, but somehow my mom calmed him down, at least enough to keep him from calling the police on my poor boyfriend."

He gently squeezed her thighs in comfort when he saw her smile falter as she brought up her mother. "He was going to call the cops on your boyfriend?"

She nodded. "I had just turned 17. And my boyfriend was 21."

"Kate Beckett!" he couldn't help but laugh slightly in surprise.

She shrugged. "What can I say? I have a thing for older guys," she nudged him playfully. "Obviously."

He chuckled again. "Well you're not 17 now. And I'm not 21."

"No, we are not," she agreed, giving him a soft kiss before carefully climbing out of his lap and off the bike. "But I still don't want your mother and daughter inside thinking about us out here having dessert before dinner."

"When you put it like that…" he trailed off, carefully getting off her bike as well.

She used the bike mirrors to straighten her appearance a bit so she didn't look quite so disheveled before turning to look at him to make sure he looked presentable. Seeing a red mark on his pulse point where she'd gotten a little too eager, she grimaced. "Well…maybe they won't notice…"

He raised an eyebrow. "Notice what?"

Her fingers gently ran over the red mark on his neck. "Um…it's not bruised yet. Just a little red. As long as the lights aren't super bright, I think it will probably be okay."

"You gave me a hickey?!" He wasn't sure whether to laugh it off or worry about having to suffer through dinner with his mother and daughter and hope they didn't see it.

"Not on purpose!" she laughed softly. "I've got concealer if you're worried. It's in my makeup bag in the bathroom. Just go to the bedroom and fix it, and I'll tell them you're just taking care of our jackets and will be right out," she told him, slipping off her jacket and handing it to him as they headed inside.

xxxxx

The next chapter will either start at the end of Memorial Day weekend or right after it's over, and then there will probably be a little bit of a time jump.

I hope ya'll enjoyed this one…it was fun to write!