A/N: Phineas and Ferb was one of my favorite childhood shows, and still remains so to this day. I had this written out a long time ago (several years in fact, but never got around to fully realizing it as a full-blown fanfic. As of right now, this just remains a one-shot. If the reception is good enough, I will make this a chaptered story. Please tell me what you think!

A/N 2: This is only semi-canon to the series. This story revolves around Isabella and the pain she suffers from Phineas' unreturned affections.

The Pang of Unrequited Love

Isabella squeezed her pillow tightly as the sobs racked her body. Stupid Phineas! She felt like a knife was tearing at her chest. All these years and he still didn't understand how she felt towards him. She sniffled and moaned into the cotton. Great, now she had a headache. Stupid Phineas.

Phineas…

Isabella had been in love with him for so long. She had hoped that by now he would have noticed her. After all her attempts to make him notice, still nothing. She screamed into her pillow and beat the cushiony mattress, and began crying some more. Eventually her tears subsided into sleep, though it was only 3:30 in the afternoon.

Summer, 5 years ago…

Isabella, age 12, skipped merrily along the sidewalk towards Phineas and Ferb's house, a popsicle in her mouth. She was especially happy because today was the day she would finally get to spend time alone with Phineas! She peeked her head around the corner of their fence and saw Phineas alone in the yard, sitting under the giant oak tree. She stifled a squeal of delight and skipped into the yard.

"Hey, Phineas!" she chimed. "What'cha doin'?"

Phineas smiled and looked up.

"Oh, hey Isabella! Nothing much. Just trying to figure what to do today. Wanna help me brainstorm?"

Isabella rocked back and forth on her heels, her hands behind her back.

"Actually, um, Phineas, I kind of had an idea for something we could do today…"

"Okay, cool! What is it?" Phineas asked, getting up and stretching.

"Well… I was hoping you could help me sell lemonade…"

Phineas grinned.

"Sounds like fun! Lead the way, Isabella!"

Isabella smiled widely and grabbed Phineas' hand, leading him to the lemonade stand. Phineas laughed at her enthusiasm and followed her down the street. The hot sun beat down as they squeezed the lemons into the water and mixed it. Isabella held out a cup for Phineas. Phineas reached out to take it but Isabella shook her head.

"Open your mouth, Phineas!" she said.

"Um…okay," replied Phineas, confused. He did as told and Isabella put the cup to his lips. Phineas swallowed the cool, refreshing lemonade and wiped his mouth off. "Thanks, Isabella! It was great!"

Isabella blushed and giggled.

"Aww that's so sweet!"

Both children jumped and looked at the speaker. A woman in a yellow sun dress walking her dog.

"I just love young love!" she said. "And lemonade! Say, aren't you too young to be operating your own lemonade stand?"

Both replied, "No, no we aren't!"

"Well, good, because I would like some lemonade, please!"

The woman handed over 50 cents and took a cup of lemonade. Isabella put the coins in her jar and grinned broadly.

"Thank you! Enjoy your lemonade!"

The woman nodded and left. It was at this point that Phineas noticed something.

"Hey, where's Perry?"

Isabella shrugged.

Behind the lemonade stand…

Perry the Platypus snuck into the bushes, and whipped out his agency hat. He tapped a specific part of the soil with his foot and shot into a tube that led to an elevator. In the elevator he encountered Pinky the Chihuahua, to whom he tipped his hat.

Back at the lemonade stand…

"Huh, I wonder where he is," Phineas pondered.

Isabella sighed dejectedly. Phineas looked at her.

"What's wrong, Isabella?" he asked.

"Oh, it's nothing. It's just that… well, I thought this would be more fun, y'know?" she replied.

"What do you mean? I'm having a great time!" Phineas said.

"Really?"

"Yeah! Me, you, homemade lemonade, that thirsty gorilla!"

"Thirsty gorilla?"

Phineas and Isabella looked in front of them to see a gorilla man stealing a glass of lemonade.

"What? Even gorillas get thirsty, y'know!" said the ape defensively before running off screaming.

Phineas turned to face Isabella.

"The point is, I enjoy just hanging out with you, Izzy. Building giant contraptions is fun, but sometimes I just like to kick it down a notch and just spend time with my best friends. Like selling lemonade."

Isabella smiled, a tear about to form in her eyes. He called her Izzy! He hardly ever called her Izzy. She cherished the nickname.

"Okay, Phineas…"

"But…if you really wanna start selling lemonade, I think I have an idea!"

"What is it?" Isabella said, now interested.

Phineas cracked a grin and pointed across the street at the ice cream parlor.

"Isabella, I know what we're gonna do today!"

Back in the present…

Isabella awoke with a start. She looked at her clock. It read 6:46 PM. She had been asleep for nearly three hours. Somehow, she did not feel any better. In fact, she felt considerably worse. She'd had a dream of what could be considered the closest thing to a date she had with Phineas. Isabella sighed deeply and grabbed her plush toy kitty, holding it close as tears welled up once more.

Summer, 10 years ago…

It was Isabella's 6th birthday, and they were holding the party in her backyard. Isabella was getting restless, tugging on her mother's dress, and bouncing up and down.

"Mommy, mommy! When will Phineas and Ferb get here! I want to play with them!" she cried out. Vivian chuckled and picked her up.

"Soon, mija, soon. Why don't you go sit on the front porch and wait for them?"

"Okay!"

With that, Isabella sprinted to the front door and ran outside. She plopped down on the front porch, and swung her legs back and forth, humming nonchalantly as she waited. A few minutes later, Phineas and Ferb were darting across the yard to greet her. She squealed in elation and hugged Phineas.

"Happy birthday, Izzy!" shouted Phineas. Ferb remained silent, watching the two hug and giggle. Linda ushered the three inside and started chatting with Vivian.

The three youngsters ran into the sitting room to play while their parents continued preparing food for the party. Isabella got out her favorite toys and put them on the floor to play with while Ferb sat on the couch, preferring to observe. Phineas sat in front of Isabella, who looked up at his deep blue eyes, entranced.

"I got you a present Izzy! Here, open it! Open it!" chanted Phineas, holding a small wrapped gift box.

Isabella giggled in delight and accepted the present, tearing off the gift wrap as Phineas, noticeably excited, bounced up and down. Out of the box came a plush kitty. Isabella screamed in joy and tackled Phineas in a hug.

"Thank you Phineas! Thank you!"

Linda and Vivian looked on from the kitchen, smiling.

"They're so getting married one day," said Linda.

"Oh you know it, compañera," replied Vivian.

The present…

A tear stained the soft toy as Isabella cried silently, the memories of her and Phineas' past flooding her psyche. Will this torment ever end? Is her hope for nothing? She couldn't help but think so. Why did love have to hurt so much? What did she do to deserve this? A soft knock on her door interrupted her thoughts.

"It's open," she said dejectedly.

"Mija," whispered Vivian. She walked over to Isabella and laid her head on her shoulder. "Mija it's okay. I know it hurts, but it will end. I promise."

Isabella's mouth trembled once more and she fought the urge to cry again. Vivian hummed a lullaby from her childhood in an attempt to soothe her daughter.

"Mama I love him…I love him so much…" Isabella whispered, burying her head in Vivian's shoulder. Vivian stroked Isabella's hair as she cried.

"I know, child, I know. But remember, even if he never returns your feelings, no boy could ever ask for a more loyal, beautiful and caring friend as you."

Isabella wiped away her tears and took a deep breath.

"Thank you, mama."

Vivian kissed her daughter on the top her head and got up.

"Now, come, mija, I need help with these rolls!"

Isabella laughed curtly and got up. Halfway to the door she paused, and looked in her hand. The plush kitty. She smiled faintly and put the toy in her pocket, patting it for good measure.

Stupid Phineas.

A/N: How was that? Reviews are appreciated!