Summary: Castle was done giving her space, sitting back and watching her fall for the charms of other men. This time, he was going to take a stand. SPOILERS FOR 4x20!

Author's Note: SPOILERS FOR 4x20 (in case you missed that above). The idea for piece was spawned by the spoiler released a couple weeks ago that said that Kate might be attracted to the Scotland Yard detective who's coming to the show. I'm kind of not okay with that (though I trust the writers completely), so I decided that this was the perfect opportunity to write jealous Castle!

Special thanks to shhhhhcastleison, one of my lovely followers on Tumblr, for coming up with the title for this one shot!

Disclaimer: Yeah, no. Just, no.

No Matter What

Richard Castle was angry. No, scratch that. He was furious. Seething. Overflowing with jealousy.

The team at the Twelfth was currently collaborating with Scotland Yard Detective Colin Hunt, and the man had been shamelessly flirting with Kate since the moment he stepped off the elevator yesterday morning.

And to make matters worse, she had been dishing it right back. She had been laughing at his jokes, smiling as she talked to him, and when she started building theory with him, it was as though Castle was not even in the room.

Now I know what she felt like when I was building theory with Jordan Shaw, he thought with a self-deprecating chuckle. No wonder she was so angry.

And today, for the last four hours as they dug through financials and phone records, old reports and eyewitness accounts, Castle had been forced to just sit there and watch the attraction unfold. Watch Kate fall for his charms and his sexy British accent.

Now, they were away from Detective Hunt for the first time all day, and Castle planned to make his feelings excessively clear. Kate may have been able to pretend she was not jealous of him and Jordan Shaw, but he apparently did not possess the same level of self-control.

Castle and Kate stepped out of the precinct and into the cool spring air, and the moment they were out the door, Castle grabbed her arm and tugged around the corner, out of view of the busy sidewalk. He turned abruptly, hands finding Kate's waist as he pressed her up against the brick wall, and she did not have time to protest, did not even have time to think, before his lips were on hers, hot and demanding, kissing her more thoroughly than she had been kissed in a long time. His hands dug into her hips, his body surrounding hers, and Kate could do nothing but kiss him back just as fiercely.

She swiped her tongue across his bottom lip, begging for entrance, but rather than granting her access, Castle pulled away.

It would have been so easy to get lost in her kiss; in fact, he already almost had been. But he had a point to make and if he kept kissing her, all coherent thought would vanish.

"Dammit, Kate," he said hotly, hands still on her hips, holding her in place. His eyes were dark and possessive and, God, he was so attractive when he was jealous.

"I know you remember the shooting," he continued before her thoughts had a chance to stray any further. "I know you remember what happened. All of it." The way he was looking at her...no, looking through her...made it quite clear to what he was referring. "You know how I feel about you. And if your goal is to avoid that and ignore it and flirt with other guys until I get bored and walk away, then you're mistaken. I'm not going to give up, Kate. I'm not going to get bored and just leave. That's never going to happen."

She opened her mouth to speak, to say...actually, she had no idea what she was planning to say, so it was just as well that Castle barreled on.

"Why do you think I've stayed all this time, spent my days following you around? Because I love you. I love being around you. But if I'm truly not what you want, then please just be honest with me so I don't keep getting my hopes up."

"Castle..."

He silenced her with a finger over her lips, gentle, a complete contrast to the heated passion of the kiss and his angry words. "Tell me, Kate. Because if you honestly want me to be here with you, then I'm not going to sit back and watch him and his English accent try to steal you away from me. You're mine."

If he had not been angry and jealous, those last words would never have come out of his mouth, not in a situation like this. But he was so far past censoring himself right now. He would say whatever it took to make her believe that his feelings were real and powerful. To make her see what they could be, to convince her that it was better than whatever she might think she felt with this other guy.

Yes, he was jealous and it was petty, but he was sick of idly watching her flirt with other men. He had been patient, given her the time and space she asked for. But now it was time to start fighting for it. For her. For them.

"I..." she stammered, still reeling from the impact of his words, the fire in his eyes as he spoke them. "I'm not..."

He kissed her again, rough and possessive. "Tell me you don't feel that," he challenged as he pulled away, breathing heavily, eyes dark with desire. "Look me in the eye and tell me that what we have is no different from what you've had with anyone else."

When she did not speak right away, he continued, voice taking on a hint of desperation.

"I'm right here, Kate. I'm here by your side every day and I love you so much more than you know. So please stop looking the other way."

Those words seemed to hit home and Kate sobered. She had been unfair. So unfair, by keeping him guessing about her feelings. By not telling him that she loved him back just as strongly.

And now, Richard Castle, author extraordinaire who could have any woman in New York City, was begging her to give him a chance.

God, she felt horrible that it had come to this.

Kate shook her head slightly, realizing that she still had not answered his question, and he was waiting for her with an agonizingly painful look on his face. She needed to find words, and soon.

"I...can't," she stammered. Not the ideal way to start, but it was the best she could manage.

"Can't what?"

"Tell you that. I can't, Castle." At least the words were flowing now, though not quite in the correct order.

"Why?"

She could tell he was trying to hide the sinking feeling that was threatening to overwhelm him, and it broke her heart to know that she had done this to him. She held in her hands the power to completely break his heart, and so far, she had been reckless with it. Selfish. Had put her own needs ahead of his feelings.

God, how could he even still love her after all of that?

"Because it's not true. And I'm...I'm done lying to you." She met his eyes, held his gaze steadily. Her heart was pounding out of her chest and she was fairly certain her hands were trembling. So much was riding on this admission, on his reaction to her words, to her lie.

But it was now or never, because she wanted him here, needed him in her life. And he deserved the truth, and everything else she had to give him.

"I did hear you. And I do remember, Castle. I never forgot." She lifted a hand, cupped his jaw. "And I love you, too. So much."

He should be kissing her again. That was the first thing that popped into both of their minds. He should be pressing her into the wall and kissing her senseless. And she should be returning the favor, her body wrapped around his, hands and lips exploring his mouth, his jaw, his chest, any part of him she could reach.

They had just admitted that they loved each other, and that should be cause for celebration.

But there were so many questions first, so many things Castle needed to know before he could allow himself to feel anything or react in any way. So he restrained himself, leaning away from her touch. His hands, however, remained firmly on her hips; there was no way in hell she was going to run away from this.

"Why did you do it?"

"Because I..." Kate sighed, dropped her hands to her sides.

Why indeed? She had justified this to herself a thousand times, but now, looking into his eyes, seeing the pain she had caused. It all seemed so...pathetic.

"I was selfish," she said eventually. "I was scared and hurting and an emotional disaster, and I didn't want to deal with anything else. So I pushed it aside. Pushed you aside."

She sighed heavily, ran a hand through her hair. "It was wrong of me, and I know it hurt you, but I didn't know what else to do."

Castle looked away, obviously not pleased by her excuses. "But that doesn't make it right," she added, drawing his eyes back to her face. "There was no excuse for me to lie to you like that or treat you the way I did. None. And I'm truly sorry."

When his only response was a nod of the head, she continued. In the end, explaining more may or may not help, but at least she could say that she tried.

"I told you last summer, I have that wall."

"I know, Kate. I remember, and I've been trying to respect that. I've been trying to help you with it. And now this," he gestured towards the precinct, to the man who had caught her eye the last two days, "is what I get in return."

"It's not..." she sighed, began again with more strength behind her voice, "it's not the same, Castle. Hunt and I...we're just flirting. It's harmless."

"He doesn't seem to think so," Castle countered, voice laced with obvious disdain for the man.

"Neither do you."

"Of course I don't," he burst out, exasperated.

"Well, I'm telling you now, you have nothing to worry about," Kate assured him. "I am working on that wall, Castle. It is falling down. And you're helping, too, more than I think you realize."

"And what happens when it's gone? You and Hunt walk arm in arm off into the sunset?"

Kate snorted, the thought preposterous to her ears. Though not to Castle's, it seemed, if his glare was any indication.

If he had not been so jealous, so emotionally strung out from all of this, he would have realized how ridiculous his suggestion was, but in his current slightly-irrational state, it seemed a completely reasonable conclusion.

God, she had made him so insecure, made him doubt her so much, all because of her unwillingness to open up and be honest.

Screw the wall. It was time for her to break out from behind it with a wrecking ball and stop hiding herself, her feelings, her heart.

Kate cupped Castle's jaw again, ensuring that his gaze never left hers as she spoke. "You're the only one who's ever made me want to knock it down, Castle. You're the one I've ever met who's worth it. I'm getting there. I'm so close." she leaned in, brushed her mouth across his so lightly that it could have been the gentle breeze that caressed his lips. "And I need you to know that you're the only one I want waiting for me on the other side."

That seemed to be enough, at least for now, because it was Castle who leaned in this time, fusing their lips together, soft and loving, a 'thank you' and an 'I'm sorry' and an 'I love you' all wrapped up into that one gesture.

They kept the kiss fairly chaste, considering the fiery anger and jealousy that had consumed them just minutes earlier. But they were sort of in public and they were technically still at work, and Castle did not want their first heated make out session to take place against a brick wall outside of the precinct.

Later tonight in his bed, though, or hers, would be the perfect place for such activities.

A distant ringing sound registered faintly in Castle's ears, forcing thought back into his brain, pulling him back to the present.

A phone. Kate's phone. In her back pocket, which was currently not far from where his left hand had ended up. Risking the possibility of having his ear twisted, he slid his hand into her pocket and retrieved the device.

"Castle!"

If she had been attempting to sound disapproving, she failed miserably, her voice far too breathless to be at all threatening. She snagged the phone from him, feigning anger and shooting a semi-effective glare in his direction.

"Beckett," she answered, her voice surprisingly steady now, considering. She stepped out of reach of Castle's arms, forced herself to focus.

"Yo." Esposito's voice came through the line. "Did you get him yet?"

Him? Oh, right. The suspect they were supposed to be picking up.

"Uh, no," Kate responded, caught completely off-guard. She ran a hand through her hair, down her jacket, smoothing the wrinkles created by Castle's exploring hands.

"Where are you?"

Outside.

"On the way," she lied.

"Why are you out of breath?"

"I'm not," she snapped, too quickly for it to be at all believable.

"Right."

"Espo..."

"Right, okay, just...let us know," he said in a clearly disbelieving voice.

"Uh, yeah. Bye."

She re-pocketed her phone, intentionally avoiding Castle's eyes and the smug look she was sure to find there.

Awkward. This was awkward. Two minutes ago, she had been seriously considering shirking her responsibilities and having her wicked way with her partner. Now, they had to get in a car, together, go pick up a suspect, and interrogate him. All in very close quarters. And then they had to spend the rest of the day wrapping up this case, with absolutely no privacy.

Oh yeah, and Colin Hunt was going to be there, flirting with her some more.

Yeah, awkward pretty well summed it up.

"Ummm, now what?" Castle inquired hesitantly, his hands nervously fiddling with his pockets.

Kate sighed, finally meeting his eyes. "I don't know. But we really do need to go get our suspect, so we don't have time to figure it out right now."

"No. No," he said quickly, losing all hesitance and snapping back into serious mode. "We're going to do it now, because if we keep putting off figuring us out, nothing will ever change."

"Castle..."

"No, Kate. It's not that hard. You just told me how you feel. You know how I feel. So either we don't ignore this and be together, or we do and I start trying to get over you."

As if he ever could get over her. The whole world knew the answer to that.

"You really think I'd tell you I love you and then walk away?"

"No offense, Kate, but you're not always forthcoming about this kind of thing."

She wanted to argue with his statement, but it was true.

"I want to be with you, Castle," she affirmed, surprising herself with the steadiness of her voice. It was nerve-wracking, taking this leap. "I know things between us are a mess and probably will be for a while. But yes, I want to do this."

It was terrifying. Completely and utterly terrifying. But this was Castle, and if she could not trust him to catch her, then she was hopeless. She trusted him with her life and if she could do that, she could certainly find a way to trust him with her heart. Already did, actually, even if she was hesitant to admit it.

His hands found purchase on her hips again, gently this time.

"And when this case is done, I can invite you over for dinner and wine and a relaxing evening at the loft?"

She smiled, rested her hands on his chest and leaned in for another kiss.

"Yes."

"Do I get to wake up tomorrow morning with you in my arms?" he asked shyly, and Kate smiled broadly at the unsure yet adorable expression on his face, his puppy dog eyes.

Oh, she could have some fun with this.

"That depends."

"On what?"

"On whether you let go of me so that we can go pick up our guy and get a confession out of him and wrap up this case."

He jerked his hands back from her hips like he had been burned and almost tripped over his own foot in his hurry to turn around and head for the cruiser.

Kate put a hand to her mouth to hide her smirk, and followed him, her steps slightly more graceful than his, though she had to admit, there was a certain sense of urgency in her stride now, too.

They slid into the car in unison, but before pulling out into traffic, Kate leaned over, catching Castle completely by surprise as she kissed him one last time.

When she pulled away a minute later, hair slightly mussed and lip gloss all but gone, Castle's mind was completely made up.

They were going to close this case today. And once they did, she was coming home with him and not leaving until sometime tomorrow or the next day.

He was going to wake up with her in his arms tomorrow morning, clothed or not. Whichever she was comfortable with.

Because she was his now.

No matter what.

THE END

Thoughts?