A/N: I admit, I was a little bit inspired by The Proposal for this chapter…

Castle came out onto the homicide floor with his usual tray bearing two venti-sized cups of coffee and paused beside Beckett's desk. His muse was nowhere to be seen. Usually when he arrived at the 12th, her coat or jacket would be hanging on the back of her chair. Today, the chair was empty and the desk clear of any mess that would normally signify her presence.

Spinning, he found the boys and put the tray of drinks down on Kate's desk, freeing up his hands to remove his own coat as he asked, "You guys seen Beckett? She's never this late, right?"

Ryan glanced at his watch, frowning because what Castle said was true. Beckett was usually the first person into the office, but even when she wasn't, she always arrived before eight thirty.

"She's probably just stuck in traffic, bro," Espo replied, shrugging.

"I got here okay," Castle pointed out.

"I'm sure she's fine," Ryan said. "Maybe she's just gone to work out for a bit. It's not like we're working a case."

Accepting the Irish detective's pacification, Castle sank back into his chair and grabbed the coffee labelled with his name, letting the heat of the Styrofoam infuse his palms for a moment. He'd barely been settled five minutes when his cell phone vibrated in his pocket and made him have to squirm to get the device out of his tight jeans.

Meet me outside the locker rooms. No questions.

Frowning, Castle wondered what was going on with his partner but stood nonetheless, muttering a quick excuse about needing the bathroom when both the boys looked at him questioningly.

He distinctly heard Esposito ask, "Who takes their coffee to the bathroom with them?" as he walked towards the staircase that led up to the gym and locker rooms. As promised, Beckett was waiting for him outside the women's lock room. Or at least part of her was – her head, to be specific, was poking out around the partially open door.

"Beckett?"

"Castle, I know this is totally clichéd but I literally need the shirt off your back."

He laughed, the sound dying when Kate shot him an annoyed glare. "Why? I thought you kept a backup in there." He pointed in the vague direction of the women's locker room, earning himself another steely-eyed look.

"Castle, just give me your damn shirt! You've got an undershirt on, haven't you?"

"Yeah," he muttered, tugging his open collar out so he could see the Green Lantern shirt he already knew he was wearing underneath.

"So give me your shirt."

Sighing, Castle stooped to place his coffee cup on the ground, along with his suit jacket, and began unbuttoning his shirt.

"What happened to yours anyway? You spill coffee on it again?"

"Don't laugh," Beckett cautioned, her arm coming out to warn him with a finger before the rest of her body followed, slipping easily out through the crack between the door and its frame.

Castle had to bite his lip but the shortest of snorts still escaped him. He couldn't help it. Not when Beckett had what looked like an entire bucket of paint down her shirt.

"Castle, I said don't laugh," she complained, crossing her arms over her midriff, before remembering the paint and pulling them back with an expression of distaste as she saw the dark blue paint on her wrists.

"Sorry, I just- So what happened?"

"Even you won't believe it," she muttered.

"Try me," he responded, finally finishing his shirt buttons and pulling the garment off.

Beckett accepted the shirt from him with a sigh, but answered anyway. "See the decorating guys downstairs?" He nodded. "One of them got a little distracted coming out of the van with an open vat of paint…"

"Distracted by what?"

"A particularly well-endowed jogger," Beckett replied, making a disgusted noise at him when he grinned and tried to imagine it.

"So then what?"

"What do you think?" she snapped. "The idiot tripped and sloshed the can right at me." Turning on her heel, Beckett disappeared back into the locker room. She'd already switched out her pants and blazer for the spares that she kept in her locker. Changing her shirt had been when she'd hit a snag, finding that there in fact was no spare blouse in her locker because she'd forgotten to replace the old one after the last time Castle threw coffee down her when they collided in the breakroom doorway.

Castle waited outside the locker room for her, leaning back against the wall as he continued drinking his coffee.

Finally she stepped out, his grey shirt tucked into the waistline of her black dress pants and the sleeves rolled and pushed up to her elbows, pulled over the top of her blazer sleeves. It looked a little baggy, but somehow it looked good too unlike his current attire. Somehow his Green Lantern shirt, no matter how cool, just looked ridiculous underneath his own suit jacket. Esposito and Ryan wasted no time guffawing at him when he went back down to the homicide floor with Beckett, making a beeline for the breakroom to make a fresh, piping hot latte for her just as an escape from their amused gaze.

A/N: Just a short chapter, but it was an idea that I found kind of funny. It had been a while since I'd written a pre-relationship chapter too so I kind of wanted to do that. I hope you enjoyed it!

Thank you for continuing to read and review, guys!

I've got a couple of chapters lined up, one of which is an idea from wendykw, but feel free to send along an idea if you have one. I kind of want to do something that would fit in with the season 7 arc too, so expect a chapter for that soonish.

(Also, happy Castle Monday! It will be a pleasure to die along with the rest of the fandom tonight!)