A/N: If you follow me on tumblr, you may have seen that I reblogged a list of prompts with the common theme of each idea being a 'post break-up AU'. I filled a total of 19 and I apologize if you've already read these, but I hope that you don't mind seeing them again. And if this is your first time coming across this series, I truly hope you enjoy it!

"I literally can't sleep alone anymore so i've shown up at your door in my pajamas, can we have one more nap together, please?"

He opens the door to see her on the other side, his heart immediately leaping into his throat, but Kate looks exhausted, drained and devoid of the myriad of emotions he had recently evoked, overwhelmed her with.

"Beckett," he addresses her, as if it's a completely normal occurrence for her to show up on his doorstep at two in the morning in her nighttime attire of leggings and an oversized t-shirt a week after their breakup.

She meets his gaze with hollow eyes, bare of makeup and allowing him to see the vivid smears of purple beneath as she shakes her head.

"I'm so tired, Castle," she rasps and his mangled heart twists painfully, breaks a little more.

He doesn't ask why, doesn't ask her to elaborate; he doesn't speak at all. Castle steps back and holds the door open wider for her to come inside. He's tired too, unable to sleep without her in his bed, without the heat of her body and the cadence of her breathing beside him, unable to find rest when their relationship - a relationship they had worked so hard and fought so long to have - is in shambles.

Kate doesn't say any more, shuffling past him and straight in the direction of his bedroom. He follows her wordlessly, watches her with the sharp ache in his chest throbbing in time with his heartbeat as she drops her coat on the couch in his office, steps out of her shoes in the bedroom doorway, so at home here all over again. But she glances over her shoulder to him when he fails to join her once she reaches the edge of his bed.

"Rick," she sighs, her exhausted eyes hooking his, reeling him towards her without his consent. "Please."

He reaches her in three long strides, waits for her to climb onto the mattress and settle on what had been her side before he joins her. Rick descends to lie on his back and the moment his head hits the pillow, her body is draping at his side and his lungs are seizing in his chest.

"Kate," he croaks, but fails to stop the curl of her leg between his, the mold of her body along his side, curves and bones all fitting back into place against him, back where they belong.

The circle of his arm around her shoulders is instinctive, unstoppable, like the fall of her head to his chest, her cheek atop his heart and her hand fisted in his t-shirt.

"I can't sleep," she admits on a sigh and he holds her tighter, presses her in closer, tries not to think about how much he's missed her. "I used to love sleeping alone, but then you just… fuck, you ruined me, Castle."

And he knows that she's no longer talking solely about her sleeping habits, that the hitch in her breathing and the brokenness of her words isn't from her lack of rest.

It had been just over a month, a single month since she had taken him up on his offer for a movie marathon, since he had kissed her goodnight at his front door, since a 'goodnight' had quickly turned into a 'good morning'. He'd had a mere three weeks with her before secrets had torn them apart again, since she discovered that damn murder board with her face plastered in the middle of it all, since she had demanded he take it down and he'd refused. Since she had told him they were really over this time and stormed out of his loft.

He doesn't truly know what they are – broken up, on a break, straddling the line between the two. All he really knows is that they can't be over, not when she's back in his bed, enveloped in his arms, making it quite apparent that she wants this to end just as much as he does.

"You ruined me too," he murmurs into her hair, pressing his lips to her crown, inhaling the scent of her shampoo. "All we seem to do. Ruin each other."

Kate releases another sigh, another weary sound, and turns her face up to bury in the cove of his neck.

"That's not true," she whispers, her eyes blinking too quickly against the underside of his jaw, her throat working hard against his clavicle. "It's just - all we're doing right now."

Castle closes his eyes, slips one of his hands into her hair and cradles her skull in his palm.

"Kate, I'm-"

"Not right now, not tonight," she rasps, staining a kiss to his throat.

Rick purses his lips, but relents, compromises. "Tomorrow?" he tries instead, feeling her tense before the breath, the fight, shudders out of her. "Please, Kate, I can't do this anymore."

I love you too much to keep going like this.

"Me neither," she confesses, flattening her palm across his sternum, splaying her fingers wide over his chest. "Tomorrow. Tonight, can we just-"

"Yes," he murmurs, planting another kiss to the top of her head, shifting his body ever so slightly to perfect the slot of her frame into his. "Tonight, just sleep, Kate."

An exhale, one he's certain is of relief, rushes out of her, pools in the hollow of his throat where the heat of her breath washes over, and she nods, begins to drift in his arms.

"You too. Sleep with me, Rick."

He's so tired, so grateful just to have her back, only if for a night, that he doesn't even fathom making a joke of her words, following them up with an innuendo. He only follows their true meaning, follows her into the desperate need for slumber.