Sorry for the errors. The inspiration just came and I had to write it down immediately. Still, I hope you guys like it! :D Enjoy!
...

The whole gang was at Kevin Ryan's wedding including Captain Gates, who was one of the last minute add-ons. Everybody was ecstatic about the event. The ceremony was moving and lovely and everyone was just in tears as Ryan and Jenny exchanged words of promises to each other. During the ceremony, though everyone was focused on the couple, their minds was else somewhere. Lanie and Esposito were now okay. They have talked things through and decided to push through with their relationship. Castle was just reminiscing on the last 2 times he has been married and got into his imagination again and thought about the things he would do differently if he ever got married again and when Kate Beckett would be there standing with him. During that moment, he stole a look for Beckett who was looking at him too. She quickly looked away. "She is so busted." Castle thought and he looked at Beckett again. Kate knew that Castle had already figured out what she was thinking. Yes, she was thinking of when her time came that she is the bride and possibly a Richard Castle with her at the altar. Her mind wandered to every detail of how her wedding would be and the words she was going to say. At that moment, the crowd erupted to applause as the couple sealed their promise with a kiss.

...

The celebration continued at the reception and the group was seated at one table including Captain Gates. At first it was a bit awkward but with a little alcohol, everybody loosened up. Kate and Castle haven't said a word yet still since there was still a program at the celebration. Come dancing time, everybody was on their feet except Kate and Captain Gates.

"Detective Beckett.." Captain Victoria Gates started.
"Please call me Kate, there's no need to be formal outside of the station, especially during this occasions." She smiled at her and shifted her position so she was facing her.
"Alright. Kate, thanks for keeping me company here at the table. I know you've been itching to dance" Gates said touching Kate's hand briefly.
"No problem, sir. It's okay" Kate said back. She looked back at the dance floor and focused on Castle and how he was really having a good time.
"You have feelings for him, don't you?" Kate's mind raced on to what to answer and immediately reveled back looking at the Captain.
"Of course not—" Kate started her defense only to be interrupted by Gates.
"Don't play me, Kate. I knew since the first time I saw you two together in my office when he let me talk to the mayor. I saw the reactions in your face." A smug smile was on Gate's face and looking at Kate's petrified face. "Why else did I let him go to Atlantic City with the boys. I also saw your reaction when I approved him going with them." Kate couldn't (or didn't) say nothing else because she doesn't want Gates to know more that what she assumes.
" You know what Kate, I have an iron fist but it doesn't mean I have an iron heart. I'm a woman too in the force and I had my moments. You're not the first woman to have fallen in love in duty." Kate was still silent but want to ask what her point was and Gates still had the smile in her face. Kate put up the courage to finally ask.
"What is your point, sir?" She is dying to know her answer. Because it will dictate on how her and Castle relationship will go. If she approves, better. If not, well, beating the odds will be harder for them.
"I'm saying that it is okay, Kate. If you two engage in some relationship, who am I to stop it." She looked into Kate's eyes. "I trust you enough to know that you can keep this relationship under control, If you know what I mean" One of her eyebrows going up.

Now Kate was speechless. She didn't know what to say or do. She didn't even notice that the music suddenly slowed. She feels like the world around her suddenly stopped with the words Captain Gates just said to her. Her thought's were interrupted with Castle tapping her at the back.

...

"Hey, Kate. Would you like to dance?" Castle at first, have forgotten that the Captain was there.
"...I mean of course If it's okay with you, sir?" Castle thought that Gates might not approve of him more If she knew that he has feelings for her. He was scared she will kick him out.
She just nodded with the flicker of her wine glass for approval. Kate then looked at Castle then to Captain Gates. She stood up and gave Gates a hug to her and Castle's surprise. "Thank you, sir. It means a lot." She whispered. "No problem, dear." She said back. Pulling away, she looked back to Castle, who's look is waiting for an explanation for her actions. Castle offered his hand to her and she took it. The moment when their hands clasp together, it brought Kate back to the moment when they were almost killed by a nuclear bomb and she felt the same thing then and now. Her heart was pounding, unsure of the things that will happen next but the different thing about now is that there was an intimate feeling with him holding her hand and pulling her towards the dance floor.

Kate put her hand around his neck and his hands on her waist.
"Don't even think about it, Castle. Or you'll get into serious trouble" she said warningly but with the hint of humor in it.
Rick smiled and said "Detective Beckett, I never.." They just laughed on it and continued to dance to the music.
"Did I mention how beautiful you looked today?" She just gave a coy smile. This is the first time he's called her beautiful.
After a while, he asked. "What was the hugging with Gates about?"
"Why? Is it bad to hug my boss?" Kate said in return. Still in her sarcastic tone.
"I mean, I think you're the only who has the courage to do that to her." Castle stated.
"Why Castle, are you jealous?" She laughed at what she said and Castle just shrugged it off.
Silence fell again between them but they continued to dance and look into each others eyes deeply as if the words they want to say was understood with how they look at each other. They were in the middle of song now when she spoke again.
"Castle," she said.
"Hmm." Castle said not wanting to ruin the moment.
"She knows." Kate said and at the moment, she leaned into him. Castle was shocked with what she just said quickly went back to reality when Kate suddenly leaned into him. He held her as close as he could.

...

Lanie was of course, the first to notice the two so close to each other, she was a grabbing a drink in the bar and when she saw them. The two guys then came also to the bar to grab something to drink and rest. "Hey you two, look at your eleven o'clock." The two looked and saw the two.
"Castle and Beckett, Man, am I just just happy for those two." Lanie said.
"Of course, we are two. They deserve this moment after everything they've been through" Ryan said.
"Wow, what a relief to see those two finally dance together. I know they've been wanting this the longest time." Esposito said. They're he heard sniffs and then turned to Ryan.
"Are you crying, bro?" Ryan could not contain the tears.
"I'm sorry, Man. The wedding had made me emotional." He said in his defense.
Then they all broke to laughter.
"I would like to propose a toast, to Castle and Beckett, for slowly beating the odds." Esposito raised his drink and the two followed. It was truly a night of celebration of love and happiness.

...

I know the ending is bad but please do comment. This is the first time I have written a fanfiction again :D

Love lots, M.