Castle was pacing back and forth in the front entry way of the loft.
"Come on Kate! We're going to be late!" he called.
She was getting ready to go to her ultra-sound appointment. Today they would find out the gender fo their baby.
"Castle we have nearly and hour before we have to be there! Chill out!" she called back from their bedroom.
"Sorry! I'm just really excited." he told her.
He got tired and bored of pacing so he decided to go back to his room and hang out with his wife while she finished getting ready.
When he walked into their room he found her looking at her belly in the mirror.
She didn't hear him come in so she didn't know he was watching her. She rubbed her belly, as she started talking to her baby in her belly.
"Your daddy is so excited to meet you. I think he wants you to be a boy since he has a daughter already, but he'll love you no matter what you are and so will I." She stopped talking and turned around to go get a shirt out of the closet and noticed Castle standing there for the first time, surprising her.
"Oh! Castle, you scared me. How long have you been standing there?" she asked sheepishly, embarressed.
"A while." He replied. "You're adorable with your bump." He siad, walking over to her and putting his hands on her belly giving her a kis on her lips.
"Now finish getting ready so we can get out of here."
Fourty-five minutes later they were in a room waiting for the doctor. Once again Castle was pacing back and forth anxiously.
"Castle!" Kate said, trying to get his attention. He was making her kind of nervous. Either he hadn't heard her or was ignoring her. But her was now playing with a model of a fetus at the time when women typically went into labor.
"Castle!" she called again,
"What?" he asked, hearing her this time. Stop playing with stuff!" she said. She felt like she was baby sitting an eight year old.
"But this is entertaining." He said, whining.
"Castle! Put- the-fetus-down!" she said, emphasizing each word.
"Uh! You're no fun!" he complained, mumbling something else she couldn't hear clearly.
"I swear you're eight years old!"
"No I'm…" he started to protest but at that moment Kate's doctor walked in, not giving him the chance to finsh, causing Kate to smirk at him.
"Hello Mr. and Mrs. Castle."
"Good morning, Dr. Moore." Kate said.
"Hello Doc." Castle said.
"So are we going to reveal the gender today?" the doctor asked as he squirted gel onto Kate's exposed belly.
At that point Castle had put the model fetus down and had sat down beside her bedside, holding her hand. Kate suddenly felt nervous, and she knew Castle could sense it.
"Yes!" they both said at the same time, causing the doctor to laugh a little.
First they listened to the baby's heartbeat, and then the moment they'd been waiting for finally came.
"Ok.." the doctor said studying the screen."It looks like you two are having.. a baby boy." He announced smiling at them. "Congratulations you two." He said as he wiped the gel off her belly.
Suddenly Kate felt tears rolling down her cheeks, surprising herself by crying. "We're having a baby boy". She said, her voice cracking. But Castle didn't notice because he was still staring at his son on the screen.
When he finally looked down and saw that she was crying, he couldn't help but tease her a little bit.
"Oh my gosh! Is the bad ass Kate Beckett Castle crying? I have to get this on camera!" he said taking out his phone.
"Castle! Stop teasing me. Its not nice." She said.
The doctor chuckled, which pissed Kate off even more. Castle kept teasing until she had had enough and smacked him hard on the arm.
"Knock it off!" she said sharply, the anger in her voice was clear.
Castle stopped immediately, a little surprised by her reaction.
"Sorry." He said.
"Whatever!" she snapped, storming out of the room.
"Well she's not happy." The doctor said.
"Thanks, because I can't see that my wife is upset!" he said sarcastically, annoyed.
The doctor's face turned red, and without saying another word he handed Castle the sonogram pictures and quickly left the room.
When Castle walked out and to the front desk, Kate was just finishing scheduling her next appointment. When she saw him she gave him an angry look and stormed out to the car. As soon as Castle got in the car she let him have it.
"I can't believe to teased me about that! It was an emotional moment I had never experienced before and you made fun of me! In front of the doctor, who laughed at me!" she was clearly very pissed off. He apologized, but she didn't say anything else the rest of the way home, and when they got home, she went straight to their room, slamming the door behind her.
He sighed and sat down on the couch. He was just playing around with her and knew it was probably her hormones that made her react the way she did. As he was trying to think of a way to make it up to her, she came out of their room and sat down beside him.
"I'm sorry for teasing you." He told her.
"No Castle. I over reacted. I see now that I'm calm that you were just playing with me." She said. She took his hand in hers and held it. Suddenly the baby kicked and made her gasp.
"What is it?!" he asked, worried. She put his hand on her belly and hers on top of his and waited. Then the baby kicked again. This was the first time he'd felt the baby kick. Kate had felt it before but it surprised her this time which is why she gasped. She saw the look on his face turn to pure joy.
"Wow! That's amazing", he said.
"I know." Kate agreed.
He started rubbing her belly
"I love you Kate." He said.
"I love you too Castle." She replied.
Castle had forgotten how amazing it felt when he felt a baby kick inside the woman he loved that he'd felt when he felt Alexis kick for the first time. The baby kicked again. Castle said wow again.
Kate laughed at that.
"Once again, I love you Castle.
"I love you too, Kate" he said, as he put her hand on top of his, where it was still rubbing gentle circles on it.
Authors Note: Next chapter has mature castle fluff. Viewer discretion is advised!