"It is so fun!" the four year old screamed, jumping into her mother's arms after cleaning off her hands.

Marc excitedly nodded his head. "So fun!"

Hotch and Emily shared a smile as the twins ran off to play with their new aunts and uncles. They had turned the entire BAU bullpen into a party room for their kids, making sure they got to celebrate their first, second, third and fourth birthdays with their father before their fifth was to come.

The twins were going to be more hyper than they ever had been before, and that's why they were being sent to their grandparents for the night.

Emily stood up straight, letting her boyfriend kiss her lips before he ran over to play with her kids. "He's ridiculous," she laughed, watching the author throw her son into the air, the biggest smile she had ever seen on the little boy's face looking to the man she had fallen in love with.

"You're lucky to have him."

The brunette turned to her ex and nodded, seeing him try his best to give her a smile. "Thank you," she said softly. "How was their sleepover the other night?"

Hotch shook his head, following the younger woman to her desk so they could sit down. "Alisanne felt better, and she obviously is better now. I was just happy she didn't get sick after the doctor."

"And Marc?"

"Was very quiet," the father nodded, seeing Jack skip around with his younger brother over by the drinks. "I can tell who's going to be the loud one in the teen years."

Emily laughed, flipping her dark hair over her shoulder as she leaned back in her chair. "I knew it from the moment they were born. Marc barely cried when I delivered him, and barely made a sound throughout the night, but Alisanne was the one who would cry bloody murder if I didn't swaddle her correctly or if I brushed her hair wrong."

Hotch smiled along with the beautiful woman beside him, looking to the little girl who jumped onto Jack's back. "Our little diva."

Biting her lip, the mother's dark eyes traced along every angle of her ex's face, her arms crossing over her chest to try and block herself off from the older man so he couldn't see the confusion sweeping over her. "I think it's a French thing," she stated seriously, waiting until the laughing man looked back to her before she pursed her lips and nodded her head. "We can blame it on France."

"Maybe it's a Prentiss thing."

Her jaw dropped, the ambassador's daughter looking to her ex with wide eyes. "Excuse you!"

The older man gave a loud laugh at the look on the brunette's face, clapping his hands together at the joy he got from seeing his ex in such shock. "Well we can't blame France if one twin turned out that way and the other didn't."

Emily glared. "Then how can we blame me?"

"They're half you and half me," the Unit Chief shrugged, sitting back in his chair and flexing his muscles behind his head. "Looks like Marcus got all of me. He's calm, cool and collected."

Hearing the satisfied sigh from the older man, Emily couldn't hold back the laughter that wanted to escape. "Yeah fucking right," she snorted, leaning forward and slapping Hotch on his shoulder.

Looking up from the four year old's playing with the toys he had gotten them, Castle saw his girlfriend laughing along with something the BAU's Unit Chief had to say, her smile wider than maybe he'd ever seen it before.

Why couldn't she smile that way with him?