I was listening to the song 'I Loved Her First' and inspiration stuck me for this one-shot. Enjoy xDDD

Disclaimer- I don't own PnF or the song.

Doof sighed as he sat down in his seat. He watched as Ferb Fletcher danced with his beautiful daughter. She was resting her head on his shoulder and he hand one arm on her waist and the other lightly holding her hand.

Ferb was wearing his black tux, and Vanessa had the most gorgeous white dress on. It was a sleeveless top, but the bottom flowed out and was covered in lace. She looked like a princess.

Doof frowned over at the couple and crossed his arms over his chest and leaned back in his chair. He knew he should be happy on his daughter's big day, but there was just something bothering him. Whenever Vanessa was around he'd put the biggest smile on his face, but when she was gone it was back to his grumpy expression. Doof had thought about shooting Ferb with an inator, but he made Vanessa happy and he wasn't going to do that to her. He was mumbling to himself when he felt a tap on his shoulder.

He turned around half expecting to see Charlene. She had been nagging him all day long to put a smile of his face and be happy for Vanessa. So he was surprised to see his nemesis; Perry the Platypus standing behind him in a tuxedo no less.

"Perry the Platypus, what are you doing here?" He questioned.

Even after all of the months that Ferb had been dating Vanessa; he still hadn't figured out that his nemesis was the pet of his son-in-law.

Perry answered his nemesis, "Krrrrrrr" He chattered.

Doof nodded his head, "I see" He shrugged his shoulders, "I'm just here to watch my baby girl leave me to go off with another man." He sighed and looked down at his lap to hide the tears forming in his eyes.

"Krrrrrrr"

Doof quickly whipped his head up, "No, I am not crying, Perry the Platypus! That's silly; grown men don't cry- especially evil scientists!" He added.

Perry rolled his eyes and handed Doof the hanker chef that was in his tux pocket. Doof took the hanky and blew his nose into it. He looked at Perry's expression, and gave in, "I just don't understand, Perry the Platypus, why does it hurt so much?"

Perry sighed and shrugged his shoulders.

"I know that Vanessa means the world to him, but she means the world to me too. I just don't think I'm quite ready to let my baby girl go."

Perry patted Doof's back sympathetically and listened to his frenemy.

"Look at her; she's so happy and lost in him that she doesn't even realize how much I'm hurting. I used to the number one man in her life, that is until he came along." He glared at Ferb.

Perry looked over at Ferb and smiled. He remembered when him and Phineas were two little troublemakers running around the house in diapers. Now they were both grown men and married. Phineas finally realized his love for Isabella in college and now Ferb was married to his childhood crush.

Perry looked back over at Doof and smiled, "Krrrrrrr"

Doof sighed and nodded his head, "I know he's a good kid. He respects my little girl and treats her how she should be treated, but I'm gonna miss her. It seems like just yesterday I was changing her diapers and feeding her bottles," He smiled at the thought of those memories, "but now she's all gown up and married."

"Krrrrrrrr" Perry chattered to Doof.

He nodded his head once again and said, "I know Perry the Platypus, she'll come and visit, but she won't be staying in my apartment on the weekends any more. She's not going to be with me when I make all my inators, when you thwart me! She'll be living somewhere else, with Ferb…"

Perry sighed. Now that Phineas and Isabella were sharing an apartment, and Ferb's was right across the hall he was always switching weeks. One week he'd stay with Phineas and Isabella and the next he'd stay with Ferb so that it would be fair. Perry was fine with this, but he missed the good old days when the boys shared a room and he could just switch during the night. When the boys would wake up and start this awesomely cool project. Of course they still built stuff, but not as much as they did back when they were kids. For obvious reasons, they had to work, paying off bills and other things that grown ups must take care of.

"Today marks the first day that she starts drifting away from me, more and more as the days go by!" Doof cried.

Perry rolled his eyes at how dramatic Doof was being. Of course Perry was heartbroken once the boys grew up, but they still had the same amount love for him back when they were younger and they always would. "Krrrrrr" He explained to Doof.

"I know she'll still love me, but he's taking her away from me. Maybe he'll know what I'm going through tone day when a miracle smiles up at him," Doof smiled and looked up at Perry, "because he's going to hate it." Doof was about to continue rambling when the music changed and Doof's face lit up, "This song reminds me exactly of the situation we're in right now, Perry the Platypus, don't you think. It's actually kind of ironic" He smiled and hummed to the music. He turned to face Perry, but Perry wasn't there; only a mindless platypus in a tux sitting on a chair next to him, "Perry the Platypus, where'd you go?" He asked looking around for Perry.

He continued to search for Perry but his head shot up when he heard his daughter's voice, "Hey Dad, do you want to dance?"

Doof smiled and looked up Vanessa, "I'd love to!" He grabbed her hand and led her to the dance floor. As they made their way to the dance floor he turned to look back at Ferb; he mouthed the words 'thank you' and Ferb gave him a thumbs up.

Once they reached the dance floor; Vanessa clasped her hands behind his neck and Doof held her by the waist, "Thanks, Dad." Vanessa said as they began to dance.

Look at the two of you dancing that way
Lost in the moment and each other's face
So much in love, you're alone in this place
Like there's nobody else in the world

Ferb sat down next to Perry and placed him in his lap, "How did I get so lucky, Perry" He asked the platypus, "I have the best father and mum, the best sister, the best pet platypus, an amazing brother and the most beautiful wife." He smiled and pet Perry's fur.

"Krrrrrr"

Ferb chuckled and said, "If only I knew what you were saying."

I was enough for her not long ago
I was her number one, she told me so
And she still means the world to me, just so you know
So be careful when you hold my girl

"What are you thanking me for, honey?" Doof asked his daughter.

She smiled and looked up at her father, "Everything, everything and anything you've ever done for me."

Doof blushed at Vanessa's reply, "It's nothing…"

Vanessa shook her head, "It is something, Dad. It's more than I could ever ask for."

Time changes everything, life must go on
And I'm not gonna stand in your way

But I loved her first, I held her first
And a place in my heart will always be hers
From the first breath she breathed
When she first smiled at me
I knew the love of a father runs deep

Phineas dashed over to his brother and smiled, "Hey bro, where's Vanessa?"

Ferb pointed to the dance floor, "She's dancing with her father."

Phineas sat down in the seat next to Ferb, "At least we know where Perry is." He remarked as he pet Perry's fur.

Ferb nodded his head, "He looks rather dashing in that tux." Ferb commented.

Phineas laughed, "Yeah, I'm surprised we actually found a tux to fit a platypus!"

"Well, after twelve hours of searching we did." Ferb chuckled.

And I prayed that she'd find you someday
But it's still hard to give her away
I loved her first

How could that beautiful woman with you
Be the same freckle face kid that I knew
The one that I read all those fairytales to
And tucked into bed all those nights

She kissed his cheek and rested her head on his shoulder, "I love you Dad."

Doof let go of her waist and pulled her into a tight hug. He kissed her on the top of the head and smiled, "I love you too, baby."

And I knew the first time I saw you with her
It was only a matter of time

I loved her first, I held her first
And a place in my heart will always be hers
From the first breath she breathed
When she first smiled at me
I knew the love of a father runs deep

"You know Ferb, I was thinking about making something awesome tomorrow. It's gonna be huge!" Phineas smiled grabbing a piece of blueprint out of his pocket and scribbled ideas on the paper.

Ferb rolled his eyes, "Phin, I'm going on my honey moon tomorrow." He reminded his eager brother.

Phineas stopped drawing and sighed, "That's right, I forgot."

"But," Ferb added, making Phineas' eyes grow wide in hope, "if we're quick, we can build something before this song ends…" He trailed off taking his hammer out of the inside pocket in his tuxedo jacket and smirked.

Phineas smiled and nodded his head eagerly grabbing cups and silverware from the table for materials. Ferb smiled and joined his brother, while Perry hopped off of his lap and landed on the ground next to the brothers.

"Wait," Phineas suddenly said and Ferb stopped building and turned towards his brother, "You brought a hammer to your wedding?" He asked.

Ferb rolled his eyes and replied, "And like you didn't have any blueprints on you that day."

Phineas smiled, "…To shay…"

Ferb chuckled and continued to build.

And I prayed that she'd find you someday
But it's still hard to give her away
I loved her first

From the first breath she breathed
When she first smiled at me
I knew the love of a father runs deep

Doof smiled as he continued to hold onto his daughter. He back over to his son-in-law and his brother. He saw the two building something on the table. He chuckled and rolled his eyes, but then someone- or he should say something caught his eye. He saw Perry the Platypus standing next to the boys on the ground.

Doof smiled in his direction and Perry gave him a thumbs up.

"Thank you, Perry the Platypus. Thank you for everything."

Someday you might know what I'm going through
When a miracle smiles up at you
I loved her first

Perry jumped back onto the table next to Phineas and Ferb, "Well Perry, looks like you'll be staying with me for the next three weeks." Phineas said.

Ferb frowned, "I'm only going to be gone for a week, Phin."

"I know, but this week is my week. Next week is yours, but since you can't watch on him I will be and then the next week it will be my week again." Phineas explained.

Ferb rolled his eyes, "So the week when I'm on my honeymoon still counts as my week even if he's staying with you?"

Phineas nodded his head, "Yup."

Ferb rolled his eyes and said, "Whatever, I'll just take him when you're sleeping."

Phineas narrowed his eyes, "You wouldn't…"

Ferb just smirked, "Oh, I would." Ferb chuckled and then turned back to his invention, but he picked his head up when he felt his brother's arms around him, "I 'ove you, bro."

Ferb smiled and hugged his brother back, "I love you too, Phin."

"Krrrrrr"

Both boys let go of each other and turned their attention towards Perry, "Come here, boy" Phineas said bending over to pick up the platypus.

They brought him ina tight hug and Ferb said, "We love you too, Perry."

Perry looked up at the boys and smiled. Now it was Perry's turn to wonder how he got so lucky.

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This was much longer then I had planned. At first Doof and Vanessa weren't gonna dance together and Perry wasn't going to share his feelings about Phineas and Ferb. Phineas wasn't even going to show up in the story, but I like this version a lot better xDDDDDDD

I did quote the song in the beginning because this song gave me the inspiration for this one-shot and it's a beautiful song.