"Don't react. Don't react, and it will all be okay." Kate gripped the sides of the sink until her knuckles turned white, rage staring back at her from the mirror. All he wanted was a reaction, and she wasn't going to give that to him. Castle's gentle knock on the door only spurred her anger and frustration on.

It all started with him. A group was piloting a celebrity mentor program in the city, and was wondering whether or not he would be interested in participating. As soon as he got the email he was talking to her about it, getting her advice and asking for her permission. "Do it." She had told him, her smile soft on her lips. "I mean, you want to, right?"

He nodded with enthusiasm, his blue eyes shining with delight. "I really do. I think it would be great!"

"So why are you asking my permission?" She pressed on, somewhat concerned. She wasn't that type of fiancee, she wasn't one to deny him what he wanted, within reason. This was entirely within reason.

His look became sheepish, and he focused his gaze on her shoulder rather than her eyes. "Well, a lot of my life involves you, including my writing process." It dawned on her, what he was asking her. "I mean, I don't expect you to let a minor accompany us to crime scenes, or watch an interrogation. But maybe they could see some of the other stuff you do behind the scenes, or you could talk to them about a career in law enforcement?" His eyes traveled up to meet hers, to see how she was processing the request. "I mean, the kid would be shadowing you with me, but we'd give them the PG tour."

Her mind raced as she considered it, all the obstacles that they would have to overcome before they could make it happen. She took in a deep breath, before answering. "I'm okay with it." His response was pretty much what she expected, a fist pump and a triumphant smile. "But," she continued, getting his attention again, "the kid's parent has to approve. And I need to clear it with Gates."

His nose wrinkled at the thought. "She'll veto it."

"No she won't! The department has hosted numerous mentor programs. I just can't spring it on her." Her hand found his and squeezed it tight, reassuring him that he could still do whatever he wanted to do. "Go contact them, get matched with a kid. I'll talk to her tomorrow."

He pulled her head toward him, pressing a kiss to her forehead. "Thanks." He hopped up from bed then, jogging to the office, where his computer rested on his desk.

Within three days he had a match. A thirteen year old boy named Jesse would be following him around. His mother had approved the visits to the precinct via email, which Castle had proudly shown her the moment he received it. They scheduled a meet with the boy in a neutral setting, a coffee shop near his school. He entered in his uniform, his dark hair slicked back, green eyes searching them out. Castle lifted his hand and waved. "Jesse?" The boy looked in their direction and grinned, making his way over to the table. He shook Castle's hand first as he sat, offering a shy wave in Kate's direction.

"So you're Richard Castle. My Mom loves your books." He dropped his bag to the floor and kicked it under his table. "I kind of wondered if you'd look as good in person as you do on the back cover."

"Well?" Her fiance puffed out his chest, his body swaying, unable to hold itself upright with his giant head.

The teen looked him up and down, taking his time to take the writer in. Kate saw Castle's confidence falter under the teen's steady gaze. Jesse leaned back in his seat when he was done, crossing his arms and making a show of the shrug in his shoulders. "Eh."

Kate snorted at that, and enjoyed watching her fiance's ego shrink back to a normal size. The boy was smirking, his arms crossed over his puffed chest, one eyebrow raised with mirth.

The barista spoke from the counter behind them. "I have coffee here for Kate and Rick."

Castle moved to get it, but Jesse stood, casting an apologetic look in his new mentor's direction. "Allow me."

"Thank you, Jesse." Kate replied, her smile genuine and soft. As the boy left, she watched her fiance shoot her a look of displeasure. She rolled her eyes, her hand playing with her ring as she sat idle. "He's a kid, and he's teasing."

The way he crossed his arms looked reminiscent of him being scolded, his petulant expression one she fully expected to see their kids some day.

"That doesn't mean he has to be mean."

Her eyes rolled back in her head again. "Please, stop being so sensitive."

Conversation ceased when Jesse returned, placing coffee cups in front of each of them. "I've never tried coffee, is it good?"

Castle shrugged his shoulders, lifting his cup to his lips. "Everyone makes id different, depending on their personal tastes. I like mine black with a few sugars." He pointed at Kate's untouched cup. "She likes hers with a whole lot of milk and no extra sugar."

She reached for her cup, her hands warming up on the cardboard. "Mine is a latte, so the kind of coffee is a little different than Castle's coffee." She put the cup to her lips, allowing the warm beverage to coat her tongue. And she had to force herself not to spit it out. The look on Jesse's face meant she didn't have to look far to find the culprit. She grimaced as she swallowed, pushing the cup as far away from her as possible. "There's salt in this." Castle took a drink from the cup, his nose wrinkling as he confirmed it. "Oh God, that was disgusting." The boy next to her was doing a pretty good job of keeping a straight face. If she hadn't spent years interrogating suspects, she would have missed the subtle tug upwards that the corners of his mouth were making, and the fight to keep them down. She pushed the cup toward Jesse, who refused to meet her eye. "Good one," she started, causing him to look up, "but see, there's a difference between you and my friends. When they prank me, they know not to mess with my coffee." She raised one of her eyebrows, hoping to instil some fear into the young man.

He grimaced, pulling the cup toward his chest. "Sorry, I'll remember that." He grabbed the cup. "I can go see if they'll make you another one!"

Kate sighed. "Thank you." She pulled a ten dollar bill out of her wallet and gave it to him. "Get yourself something too. Leave the rest as a tip."

She ignored Castle's raised eyebrows as she shoved her wallet into the pocket of her jacket. The smirk on her fiance's face wouldn't go away though, not even when she pulled out her phone and threatened to beat his score on Fruit Ninja. "It was just a harmless prank, okay?" Her voice was a stage whisper so they wouldn't attract the attention of the boy.

"Whatever you say." Jesse was making his way back toward them, Kate's new drink in his right hand and his frozen thing in his left. As he got close though, she saw him lurch forward, his frozen drink landing in her lap, the coffee and chocolate spilling out all over her pants.

"I'm so sorry!" He kept repeating it, placing her hot beverage on the table and reaching for napkins. "I swear, it was an accident!" He ran to the bathroom and returned seconds later, armfuls of paper towels in his hands. "Oh my God, Kate, I'm so sorry."

"It's okay, it was an accident." She placed napkins in her lap, to cover the stain. Her jacket would be long enough to cover it when they left. "I'm just glad it was your frozen drink and not my hot latte."

"That would stink." He agreed. Castle gathered the remnants of the drink and brought them up to the counter, muttering something about making the baristas angry. Jesse sat next to her, his hands folded in front of him. "So, my Mom told me you were a cop. Are you really going to take me to the station?"

"I mean, we were thinking about it, if that's something that interests you."

He nodded enthusiastically, his green eyes dancing with anticipation. "That sounds so cool!"

Castle had made his way over to them, a new drink in his hand for Jesse. "What are you two talking about?"

"We were thinking we might head over to the precinct, if that's okay with you." She balled up the napkins in her lap, placing them on the table as she stood. She heard snickering and the familiar click of Jesse's phone as he snapped a picture of her unfortunate wet stain. She wasn't so sure that it was an accident anymore. He want's a reaction, just don't react. She would learn that it was easier said than done.

He seemed to love the precinct, his eyes wide as he took everything in. They spent a lot of time in the interrogation room, Jesse begging to be there to see one take place. "I don't know. Sometimes they're brutal. Maybe I can arrange one in robbery." His face fell as she let him down, and he sat on the side of the table where her suspects usually sat.

"I have an idea!" Her fiance's voice made Jesse look up, his green eyes pleading for something, anything, to do. "We can do mock interrogations!" Jesse's skeptical eyebrow only spurred Castle on. "It will be fun! Just think of the most ridiculous thing you could have done. Maybe you shot John Lennon. Maybe you stole all the cookies from the cookie jar. Whatever it is, keep it to yourself." He sat himself down in the seat she usually took, folding his hands in front of him. "And I'll interrogate you and see what I can find out!"

Kate cleared her throat, her hand resting on his shoulder. "Shouldn't I be the one to do the interrogation here?"

His shoulders slumped and he threw his head back. "Come on, Beckett! You always get to do interrogations! Give me a chance!" He was whining, something that had Jesse in stitches. She couldn't hide her own smile, despite the immaturity of the whole exchange.

She patted his shoulder a few times, shaking her head and rolling her eyes. "Okay, okay. You don't have to act like a child." She headed for the door, calling back to them over her shoulder. "You two have fun. I have paperwork."

She didn't know how much time had passed, but she had made it through a couple of files before she felt a small hand on her back, dark hair peeking over her shoulder. "So cops still have to do paperwork?"

She reached her hand behind her back, pulling the sign the boy had placed on her off of her shirt. She held it up, one eyebrow raised as she studied him. "Kick me. That's the best you could come up with?" His shoulders heaved up and down, his hand held out for the sign. "Oh no you don't." She got up from the chair, making her way into Gate's empty office and shoving the sign into the shredder. She wasn't going to give it back to him just so it would appear on her back again. Jesse was looking over the reports while he waited for her to return, his head resting in his fist. She sat back down and closed the files. He wasn't allowed to read them. Even Castle needed special clearance. "Yes, cops have to do paperwork. I have witness statements, things I've logged into evidence, arrest warrants, any statement that a suspect has given me, and my own personal notes. There's a lot of it, and we are almost always behind on it."

"Gross." He moved himself to sit in Castle's chair, folding his hands in his lap. "So being a cop is cool and everything, but still a lot of hard work."

"Exactly." Her smile was warm before she looked away, sorting the files into piles so she would know where to start tomorrow.

"Warning," Castle's deep voice from behind her almost made her jump, her hand flying to her chest as her heart rate increased. "I forgot my deodorant at home so the board of health issued me this warning. Sorry."

Jesse's mouth was clamped shut, his lips covering his teeth as he tried not to laugh. Kate turned her head to face her fiance. "I'm sorry to hear that, babe. I didn't notice though."

Castle's eyes danced with mirth. "No, Beckett, that's what's written on the sign on your back."

As she reached back to take it off, she realized that she hadn't even felt his hand this time. It was hard to be upset when she was so impressed. She met his mischevious gaze, holding the sign out to him. "I asked if you could do better, and you exceeded all my expectations. Good job." This one she let him have. He folded it and shoved it in the pocket of his jacket.

Castle's hand rested on her back, which was now free of notes. "So, Jesse and I were thinking, maybe we could do something fun today! There's an arcade near his house, if you want to tag along."

"I bet I can beat you at the first-person shooter game of your choosing." Jesse piped up, hopping up from his seat.

Kate nodded, placing her files in the drawers. "You're on!" As she lifted herself though, she felt resistance, the smacking sticky sound alerting her to the substance on her chair. She ran her hands down her thighs, her fingers registering the sticky goo that was covering her ass. "Is this honey?" Jesse cackled as he nodded, pointing to the empty bottle he had left on the desk. Kate clenched and unclenched her hands, the honey more like glue keeping her fingertips together. "Okay, I think we get it, you like to pull pranks. I think I'm all done for today though." She didn't know how she kept her voice calm, because she could feel her anger starting to boil in the pit of her stomach.

Castle knew the warning signs. He approached her, one hand on her elbow, one at the small of her back. "Are you okay?"

She steadied with him there to support her, the anger dissipating. "Yeah." She sighed, her hand pulling her hair out of her face. "I have a change of clothes in my locker. Make sure he cleans my chair and then switch it with Espo's. And I am so going to kick his ass on that shooting game." With that, she waddled away, her hands out beside her to prevent people from touching her.

She did kick his ass in that shooting game. Three times. She wondered if it said something about her character that crushing him in a fictional world was the highlight of her day. In retaliation, Jesse stole her phone, tossing it between himself and a few of his friends. Usually she wouldn't care, except she had a streak. She hadn't broken a phone in years, unlike her fiance who seemed to break them every month. And if this kid ruined her opportunity to hold that over him, she would not be happy. She had already fallen on their table, pizza crushed into her chest and sodas spilled. But when she heard him tell one of the boys to go long, she finally snapped. "Enough!" She shouted as the phone left Jesse's hand. It was heading toward the fake mini-golf pond. She ran to catch it, tripping over a toddler's toy truck on the way. Castle's reflexes worked in his favor for once, his hands catching the phone just before it hit the water. He was unable to catch her though, and she went tumbling head first into the pond.

She emerged with hair in her face, sputtering, the burn in her nose making her squeeze her eyes shut. "Enough. I'm all done with this." She stormed off, past her concerned partner, without meeting Jesse's eye.

When Castle entered the bathroom, she pushed herself up from the sink, whirling around to meet his gaze. "I saved your phone." He offered sheepishly, his face making her laugh despite how upset she was.

"I saw that, thank you."

He grabbed her shoulders, pressing a tender kiss to her forehead, making all her worries melt away. He pulled away to meet her eye again, concern shining through every pore on his body. "I can take Jesse back to the loft, we can bring you some dry clothes."

"No!" Her response surprised even her, and Castle backed away as she reacted. "Castle, look at me! Imagine what he would do to our house! No, he isn't to step foot within 100 feet of our building."

"Okay, okay," he chuckled, grabbing her hand and squeezing it tight, reassuring her, "I'll take him to his house, and then return with dry clothes."

"Thank you." She caressed his cheek. She wanted to hug him, but didn't want to get him wet. That would come later. For now, this was good. "Please promise me that our future kids won't ever be this bad."

"Never. I feel bad for his parents." He opened the door, smiling back in at her before closing the door completely. "I'll be right back."

It didn't take him that long, only around a half hour, most of which she spent on the phone with her father, apologizing profusely for her rebellious stage. When she was dry, she wrapped her arms around him, giving him the hug he deserved and taking the hug that she so desperately needed.

Kate didn't think of Jesse much over the next few years. Only when her kids were being especially awful did she ever thank her lucky stars that they weren't as bad as he was. So when a man walked into her precinct almost ten years later asking for a Detective Beckett, she was never expecting it to be him. "No one has called me that in years." She held out her hand, which he shook, his eyes studying her.

"Do you remember me?"

She laughed, pulling a stray piece of hair out of her face. "I couldn't forget those mischievous eyes, Jesse." She gestured toward her office. "Come in, please."

He entered, sitting down in the chair in front of her desk. He was dressed nice, a tailored suit and a black tie, his hair slicked back. "Captain now, huh? That must be fun. How have you been?"

"Good." She leaned back in her seat, crossing her arms across her chest. "I have to say, I never thought I'd see you back here again unless it was at an interrogation."

He laughed, his face turning red as he rubbed the back of his neck. "Yeah, I'm so sorry. Not that it excuses anything, but my parents were going through a tough divorce, my older sister was pregnant, and I was feeling a tad neglected. Any attention was good attention. I look back on that period of my life as the dark ages." He met her eyes again, genuine remorse flowing through them in a way she hadn't seen when he was younger. "I actually came here today to thank you. The tour of the precinct was something I held on to. I just came from a panel interview with the secret service, all because you showed me what a career in law enforcement looked like."

Kate's jaw dropped as she watched his chest swell with pride. "Jesse, that's amazing! Congratulations!"

"Thanks. I don't think I would have done it if I never met you."

"Well, keep in touch as much as you can. Let me know how it goes. I'm so happy for you!"

They visited for a few minutes until he had to leave, something about meeting his mother for dinner. He embraced Kate as he left, whispering his gratitude to her again. She waved to him on the elevator, rushing to her phone as soon as the door closed. "Castle! I'll give you three guesses to figure out who is joining the Secret Service!"

He didn't guess correctly, even after she gave him two more.

Prompt: Hi! I saw your name on the list of authors on here who take Castle prompts, and it also seems you enjoy humor a lot. So, if you're still open for prompts, I think I may have one for you: a story featuring Beckett getting relentlessly pranked by a kid or group of kids. What do you say? :)