I don't know where I got this idea from, but here it is! I hope you like it:)

Disclaimer: I don't own Phineas and Ferb.

Phineas woke up to the usual sound of his alarm going off at exactly 7am.

"Good morning Perry!" He greeted his pet platypus. Perry chattered happily in response.

Looking over, he saw that his green haired step-brother, Ferb, was still asleep, and decided not to bother him. He walked over to his dresser and pulled out his usual orange stripped t-shirt and blue shorts.

After he got dressed he waked down into the kitchen where he was greeted by his mother and step-father.

"Good morning dear. Where's Ferb?" His mother asked.

"He's still asleep."

"Oh, well, would you like some waffles?"

"Sure!"

"Okay, here you go!"

"Thanks mom!"

Just then Ferb walked downstairs and sat next to Phineas.

"Hey Ferb! Mom made waffles!"

"Ferb, dear, would you like some waffles, too?" she asked him.

"Yes, please." Ferb answered.

After they finished eating, they headed out into their backyard and sat under the big oak tree.

"So Ferb, what do you want to do today?"

Ferb shrugged.

"Hmm... well, what do we have in the project book?"

From seemingly out of nowhere, Ferb pulled out the old, worn-out project book.

"Well... We've done most of these." Phineas said, as he flipped through the book's pages.

"Oh, here's one! Hmm... A Giant Blender?"

Ferb shook his head.

"Yeah, you're right. Why did we even put that in there?"

Ferb shrugged again, while Phineas ripped the page out of the book.

"Hey guys, what'cha doin'?" Isabella asked as she walked through the backyard gate.

Ding! It was like a little light bulb went off inside Phineas' head. "Oh my gosh, Isabella! I almost forgot! Happy Birthday!"

The birthday girl was greeted by a massive hug, which caused her face to go a shade of red she never thought possible.

"Gee, thanks Phineas, but the giant bear hug wasn't really that necessary."

The red head chuckled and let go, blushing a bit himself. "Oops, sorry."

I didn't say to stop... Isabella thought to herself.

"Well birthday girl," Her face went red again. "We need to get started on your party!"

"Oh Phineas, you don't have t-"

"Nonsense!" He interrupted . "Ferb and I are gonna throw you the best birthday party every!"

"Okay... Uh, is there anything me and the fireside girls can do to help?"

"Nope! You can't be here while we're getting everything ready, it has to be a surprise! All you and the fireside girls need to do is go get your hair done and other girly stuff like that and meet us back here by... Ferb what time is it?"

Ferb checked his watch and held up nine fingers.

"Great! Be here by three-o-clock!"

"Okay! I'll ask my mom to take me to the salon!"

She turned to leave but was stopped by Phineas' voice. "Oh, Isabella?"

"Yes, Phineas?"

"Tell the salon lady I said "good luck"..."

"For what?"

"Trying to make you look prettier than you already are..."

Her face immediately flushed a deep shade of crimson.

"Well... uh... gee... t-thanks Phineas..." Saying his name made her face redden even more. "I'm gonna uh... I'm gonna go..." Smiling and waving goodbye, she turned and left. For some some reason, Phineas couldn't take his eyes off of her.

"Smooth." Said Ferb, startling Phineas.

"Wh-what?" He asked, acting innocent. Ferb just gave him a sly grin.

"You know what." Then he returned to his novel, which again, seemed to appear out of nowhere.

"Hey where's Perry?" Phineas said nervously, half trying to change the subject, and half actually wondering.

"Agent P, Dr. Doofenshmirtz has been hidden away in his apartment for days after returning from Germany. Find out what he's up to!"

The agent saluted, and hopped on his hovercar.

When he arrived at Doofenshmirtz Evil Inc. he saw a familiar contraption on Doof's balcony.

"Ah, Perry the Platypus!" said the evil Dr. Doofenshmirtz, when Agent P jumped off his hovercar. "How nice of you to come! Too bad I have to trap you!" Just as he said that, he pushed a button the brought a net up from the floor, trapping the poor, unsuspecting platypus.

"Sorry for the lame trap, Perry the Platypus, but I've just been working so hard to fix my rain-inator!

Rain-inator... wait, I thought I got rid of that thing! Perry thought to himself.

"You see," Oh great here it comes... "When I visited my mom in Germany last weekend, I saw it, just sitting there behind the airport! Didn't you tie it to an airplane or something?"

Perry didn't answer, he was too busy looking for a way to get out of the trap.

"Okay well, anyways... Today my brother Rodger is getting married to his precious fiance, and he didn't even think to invite me! So..." Doofenshmirtz said as he uncovered his 'rain-inator'. "I put the rain-inator back together, so I can make it rain all over his wedding ceremony!" He laughed an evil laugh and then pressed a button that sent half of the floor of his balcony flying up into the air.

"Now, Perry the Platypus, if you'll excuse me, I have a wedding to ruin!"

And with another evil laugh, he flew away, causing to rain under him, where ever he flew.

How can I get out of this darn thing? Perry thought, frustrated. Hmm... He examined the thread that the net was made out of. Looks breakable... He started picking at the knots in the net, and soon enough, he was free.

Now... He whistled for his hovercar, and it somehow responded and flew towards him. Where did he go? Realizing it was hopeless to go after him now, he flew home.

"Okay, I think that's it!" Phineas put the finishing touches on Isabella's giant birthday cake, and stepped down from the ladder.

"Well, Ferb, she should be here any second now. Oh there you are Perry!"

Isabella was in the car on her way back from the salon and she couldn't be more excited. Her hair was done in loose, beautiful curls, and she was wearing her prettiest dress. The salon lady asked her if she wanted make-up, but she turned it down. She was only 11, she didn't think she needed make-up.

She pulled up into her driveway and when she opened her door her mom said "You go ahead, I'll be over there in a bit."

Isabella smiled and slowly walked over to the Flynn-Fletcher backyard. She took a few deep breaths, opened the gate, and-

"HAPPY BIRTHDAY!" All of her friends shouted and ran up to greet her.

"Wow... Isabella you look great!"

"Thanks Phineas." She smiled and blushed a bit.

"Now come on, we've got a surprise for you."

"Okay! Let's g-"

"Nuh,uh," he interrupted. "Close your eyes."

"Oh, come on, Phineas!"

He laughed. "Fine, I'll close them for you!" He covered her eyes with his hand and led her with his other one.

He led her around to the other side of his backyard where her surprise was waiting.

"And... SURPRISE!" He uncovered her eyes and let go of her hand (much to her disappointment) leaving her to stare at what was in front of her: a giant, 1...2...3...4- 7! layer birthday cake that had "Happy 11th Birthday Isabella!" written across the middle layer.

"Oh, Phineas!" She was so overwhelmed, she pulled him into a massive hug that made his face go as read as a tomato.

They pulled apart and Phineas said "You're welcome Is-" He was interrupted by a sound coming from the sky. "Hey, what's that noise?"

As soon as he said that, Isabella felt something wet fall on her head.

"I... Is that rain?"

Phineas gasped and Perry slipped away unnoticed. "Oh no! It's gonna ruin the cake! Quick, someone cover it up!"

But it was too late, the frosting had melted and the cake was all soggy.

"Isabella... I'm so sorry..." Phineas said, gloomily.

"It's alright, Phineas. It wasn't your fault."

"Yeah, but now the party's ruined! We worked so hard to make sure you had the best birthday ever!"

Isabella sighed and thought for a second. "Ooo I know!" she said. "We can just continue the party inside!"

"Great idea! You go inside and help everyone set up, while I stay out here and clean up everything!"

"But Phineas, it's raining! You'll get all wet!"

He looked down at his drenched clothes, back up at her, and made a face that said Really?

"Good point... well, are you sure? We could just clean up after the rain stops."

"Yeah I'm sure. Now go help them set up inside."

"Okay." She did as she was told, and walked inside.

After the finished setting up for the party, Isabella tried looking for Phineas, but she couldn't find him anywhere.

"Hey Candace, have you seen Phineas?"

"No, I thought he was with you?"

"Uh,uh," she shook her head. "He stayed outside to clean up what we didn't save from the rain."

"Why did he want to stay in the rain?"

"I don't know, but he insisted."

"Hmm... well he might still be out there."

"Yeah, maybe, I'm gonna go look for him."

With that, she tuned and left, leaving Candace with a sly grin.

Isabella walked through the rain, in search of the boy who mattered most to her.

"Phineas! There you are!" She called out in relief when she spotted him sitting on the curb.

She sat down next to him. "Hey, Phineas, what'cha doin' out here?"

"I don't know, Isabella, I'm just... thinking..."

"Would you mind telling me what about?"

He just sighed.

"Look, Phineas, I'm sorry about the cake, I know you must've worked really hard on it. But you have to cheer up! Please? … For me?" She smiled at him, and he looked up at her. "I mean it is my birthday and all..."

The red head chuckled and said "Okay... come on, let's get out of this rain."

"Great!" Isabella exclaimed as she jumped up from her spot on the curb.

"Isabella...?" Phineas called out tentatively.

"Yea, Phineas?" The girl turned around, confused.

Before she realized what was happening, she felt the warmth of Phineas' lips on her own mixed with the taste of the rain. She stood there, kissing him passionately, and cherishing the moment she's been dreaming about for years. Desperate for air, the birthday girl pulled away from her first kiss.

"Come on," Phineas said, with a huge grin on his face. "Let's go inside."

He grabbed her hand and led her inside where the rest of the Fireside girls were watching the whole thing from the window.

I'm soooo glad I finally finished this! Some of it may sound familiar, some of it may not, but that's probably just because I've read a lot of Phinabella stories the past few days, so sorry if I stole part of your story w/o realizing it.:) I also have an idea for another Phineas&Ferb story, but it won't be Phinabella, it's gonna be a self-insert fic on me and Ferb:D I love Ferb he's so awesome:P But I won't start working on that until I finish my Resident Evil story, that I haven't published yet, but I'm almost done, I swear! Anyways... See that little gold button right there? Do you think you could press that for me? Pwease? :D Oh and you get a free cupcake if you figured out what her birthday present was ;)