Title: This is about a girl, isn't it?

Disclaimer: This is a piece of fanfiction. All the characters appearing in the following story are copyright of Disney Television Animation/The Walt Disney Company. No infringement of these copyrights is intended, and is not authorized by the copyright holder.

Notes: Phineas, Ferb and Isabella are probably roughly 16 / 17 in this story. I'm thinking maybe their sophomore or junior year of high school? Phineas still developed a crush and Isabella still gave up on pursuing Phineas once they got to highschool, so a year or two prior to this story.

Also: Ferb does a lot of talking in this? Sorry if this bothers you! I just couldn't really figure out how to do this while only giving Ferb two or three lines. So, yeah, he talks a lot!

Phineas could not concentrate.

Carving the tiny clay figures for their history project (a miniature set of the Colosseum full of moving figures and mini gladiator fighting action) was supposed to take them only an hour when using the handy machines they built just for the purpose.

It was half an hour later and while Ferb had been keeping up his numbers as expected, Phineas had only had a handful of usable figures to show.

And he needed 25.000.

It wasn't like he wasn't trying, he really was trying to do his best, but he got distracted. Lost in thought. He'd feed some clay in the machine and his mind would wander back to third period, when Dylan turned around in his seat and boldly asked Isabella out on a date. And before he knew it, he had accidentally overfed the machine, which promptly spit out five hundred deformed mini figures.

He gave an entirely unamused Ferb a sheepish grin, and mushed the misshapen figurines back together into a big lump he could feed right back onto the machine. This time he made sure to add just the right amount of clay, selected the mold he wanted and pressed down the button. He was supposed to hold it for five seconds. One, two, three - The thing is, Isabella didn't say no. She didn't say yes either. It happened in the middle of class, and instead of saying yes or no, she hissed "Seriously, Dylan? Here? You thought now would be a good time to ask me out?" and Dylan just shrugged and said "Sure. So, yes or no?". But before Isabella could answer, Mrs Martin reprimanded them for not paying attention in class, effectively cutting off the conversation. And then - Ferb slapped his hand away from the button. The machine was kind of smoking and yeah, Phineas had definitely been pressing the button for over five seconds.

Visibly annoyed, Ferb opened the machine, took out charred, brittle, unusable figures Phineas had just created and threw them in the trash. With a stern look, he handed Phineas new clay.

"I know, I know, I'm sorry, it won't happen again!" Phineas said. Ferb just rolled his eyes and went back to his own work.

Okay, this time he'd do it right. Put the right amount of clay into the machine, select mold, press button down for five seconds. Yay, perfectly made figures. He went to put them on the conveyer belt, when his brain jumped back to Isabella, who after being reprimanded by the teacher for talking in class (unfair, if you asked Phineas, since it was Dylan's fault in the first place), she wrote down something on the edge of her notebook, which she then tore out and tossed above Dylan's head right onto his desk.

"Phineas."

And since Isabella had been the first person out of the classroom after class ended - Dylan, by the way, calling "Isabella, wait!" and taking off after her - Phineas did not get a chance to ask what she wrote. And then he had not seen her for the rest of the day, which wasn't that unusual since Wednesdays they shared no more classes after third period and they didn't even walk home together because of all her extracurricular activities.

"Phineas."

Which meant that he could not help but imagine all the different things she could have written and the scenarios they could result in. Isabella could have agreed to a date!

"PHINEAS!"

Phineas startled and dropped the figures on the ground, where they shattered into little pieces.

"…oops?" He turned around to find his brother staring at him, one eyebrow raised.

Ferb pointedly looked at the mess on the floor, then towards the trashcan already overflowing with Phineas' previous mistakes, before finally looking at the quickly diminishing block of clay they bought. With an annoyed sigh, he crossed his arms, leaned against the machine and waited for Phineas to explain himself.

"I keep getting distracted! I'm really sorry, my head is just not in the game today." Phineas said, rubbing his eyes in frustration.

Ferb motioned for him to go on.

"It's nothing serious, I'm just- my thoughts are somewhere else today, is all," he continued hesitantly.

Ferb's stare was silently urging him to continue, but Phineas had no idea how to explain any further without either outright lying or… risking to reveal his stupid crush on Isabella.

"It doesn't matter. Let's just go back to work, we need 50.000 figures total if we want to show how many people fit into the colosseum and-" He stopped abruptly when he felt Ferb's hand on his shoulder. Reluctantly, he faced Ferb again.

"You know you can tell me anything. Whatever it is, I'm listening."

For a second, Phineas imagined it. Telling his brother about his embarrassingly huge crush on the girl from across the street and he just- couldn't. He could barely even think about it without freaking out, trying to form actual words and sentences seemed impossible.

"Oh my God," Ferb said, his eyes wide and his stance loosening, "This is about a girl, isn't it?"

Phineas mouth fell open in shock. For a few moments, they just looked at each other in stunned silence. How could Ferb possibly know…?

An affectionate smile came over Ferb's face. "It's all over your face, little brother. Come on." He grabbed Phineas' arm and led him inside, up to their room. Once there, he pushed Phineas in the direction his bed and went to sit down on his own. Still not entirely with the program, Phineas sat down as well.

"So, tell me about her."

Phineas opened his mouth, but nothing came out. The seconds ticked by.

"This is not going to be easy. How about you tell me what exactly happened today that bothered you so much?" Ferb asked, not trying very hard to hide his amusement that it was his brother for once, who was lost for words.

This time though, the words basically shot out of Phineas' mouth without any conscious thought.

"Another guy asked her out today."

"Ah, I see," Ferb answered, his tone gentle. "And what did-"

"It was smack in the middle of class too and I have no idea what she answered and it's been driving me absolutely crazy. Because what if she said yes? I can barely wrap my head around her being with someone else in theory, I don't think I can handle witnessing it first hand without possibly dying of heartbreak."

Ferb frowned. "Okay, so-"

"And I can't stop thinking about it! I can't stop thinking about her! She is so beautiful and resourceful and while Dylan is a great guy, don't get me wrong, he is in no way good enough for her."

"Dylan? Isn't he into-"

"I'm a terrible actor! There is no way I can convincingly pretend to be happy about any of her future relationships! She knows me! She will know I'm jealous. She won't want to be friends anymore!"

"You can't possibly be talking about-"

"I have to reign this in. This has to stop right now. This is getting out of hand, right? We're friends, best friends. That's great, amazing even. I should stop wanting more than that. I should just forget I ever even entertained these thoughts."

"Isabella."

It was as if the name filled him with electrical charge. He jumped up, since he suddenly felt twitchy all over.

"What?" he asked.

Ferb was looking at him, but it was as if he was seeing right through him. Wordlessly, he lifted his hand and pointed out of the window to the house across the street.

Phineas was speechless, but eventually he managed the tiniest of nods.

Ferb beamed. "That's bloody fantastic!" he shouted and jumped up. "You have to tell her!"

Phineas physically recoiled. "No! Are you crazy? Definitely not!"

Ferb's smile melted into confusion and he looked at his brother questioningly.

"I just- I can't. I am so deep in the friendzone there, bro. I am not even sure she recognizes me as male much less a potential romantic prospect. It will just make things weird and awkward and she's so nice. She would force herself to continue being friends with us, despite feeling super weird about me having feelings for her and just- no. No. I won't do this to myself and I definitely won't do this to her."

Ferb just stared at him blankly. "You have got to be kidding me."

"Just let it go, bro, okay? Let's get back to work- Ferb. Ferb, where are we going?"

But Ferb was a man on a mission. He had packed Phineas' arm in a vice grip and bodily dragged him down the stairs and out the front door.

"No!" Phineas said, recognizing their destination. "Ferb, don't do this!" He started struggling in earnest, but Ferb was so dang strong. He never wanted to curse his brother's awesomeness before, but now he came very close.

Despite Phineas doing his very best to pull them back towards their own house, they marched across the street and straight into Isabella's backyard.

The girl in question was doing homework at the picnic table on her patio, when she noticed them coming in. She put her pen down and smiled. "Hey, guys! Whatcha do-"

"DON'T LISTEN TO FERB!" Phineas interrupted, struggling more than ever before to get out of the situation.

"What?" Isabella said with a laugh and got up. She walked right over to them, all the while Phineas babbled on about Ferb having fever dreams and hallucinations and that he was making up ludicrous stories that held absolutely no truth whatsoever.

"Okay, what's going on with you two?" She asked.

Finally, Ferb let him go. But before Phineas could make a run for it, Ferb said the craziest thing yet:

"So, here is an interesting factoid: Isabella has been madly in love with you for years." He motioned between the two of them. "Discuss." Then he turned around and left the two of them alone.

Just left, as if he hadn't just dropped the bomb of the century.

Jaw dropped, Phineas turned to Isabella, who was looking at him with such absolute terror that he immediately knew that Ferb had not been kidding.

"Oh God, this is a nightmare," she breathed voicelessly. Phineas not so much heard it as saw her mouth the words.

In that moment, what Ferb said finally registered in his brain.

"No…" Phineas said very slowly, still processing, "…no, it isn't."

Isabella was in love with him.

And he was in love with her.

They were in love with each other.

He gasped at the realization. Isabella still looked absolutely horrified, but he was too elated to take note of that.

He grabbed Isabella by the shoulders and looked her straight in the eyes. "No, it really, really isn't! Isabella, don't you get it? This is the best thing that has ever happened! We're in love with each other!" He whooped loudly, and pulled her into a crushing hug that literally swept her off her feet.

She let him hug her for a few moments, before pushing him away, but only far enough so she could look at his face. She still looked shell shocked.

"I need you to repeat that, because I don't think I heard you right."

He laughed. "I am so, so, so in love with you, I've been going crazy with it for months."

"OH MY GOD!" Isabella squealed. Then she literally jumped him, flinging her arms around his neck. Since he hadn't been prepared for quite that much enthusiasm, he lost his balance and the two of them tumbled to the ground, her on top of him.

"Are you okay? I am so sorry! Did I hurt you?" Isabella asked, about to climb off him, but he quickly pulled her back down.

"Trust me, I've never been better," he answered with a smirk. She blushed and returned his smile.

"Me neither," she replied. She bit her lip. "I am going to kiss you now," she continued, her voice sounding more confident than her expression betrayed her to be.

Phineas took a sharp intake of breath, his heart pounding a mile in a minute in his chest.

"Okay," he whispered, lifting his head and tilting his chin. He knew he was supposed to be closing his eyes there somewhere (that's what they do in movies, right?), but he didn't want to miss a single second of Isabella licking her lips and slowly lowering her face down to his. Her eyes were switching back and forth between holding his gaze and looking at his lips. She gave him the tiniest smile, and that's it. He was about to give her a little tug to pick up the pace a bit, because even a second without her lips on his felt like a year at this point, when his brain made another connection.

He sat up suddenly, Isabella jerking back in the process to avoid being smacked in the face.

"You've been in love with me for years?" he repeated Ferb's words, this time the full implication settling in.

"Yeah, I- you really didn't know? I thought I was being so obvious," Isabella answered.

"How many years are we talking? Like, pre-highschool years?" he asked because he absolutely had no clue that she was in love with him at all. Since freshman year he had been watching for even the tiniest of signs that she liked him back, he would have noticed for sure.

"Geez, you really had no idea. I'm talking actual preschool years here, Phineas. It's been, like, over a decade at this point," Isabella said, rolling her eyes.

That completely floored him.

"What? I just- no way. That long? Why didn't you - you never said a word!"

Now Isabella looked annoyed. "Seriously? Everyone knew, Phineas! I was not subtle. Pretty much the only thing I didn't do was outright come out and confess and with you being a big, oblivious goober, there was no way that was going to end well for me. I mean, God, remember Paris? Remember when I made that little garland with your face and hearts? Remember that Halloween where I dressed up as Cinderella and was constantly losing my shoes in front of you? Remember Candace's seventeenth birthday party when I-"

"Okay, I get the picture, I'm an idiot, please stop." Phineas finally interrupted, hiding his bright red face in his hands.

"Why are you embarrassed?" she asked, amusement coloring her tone, "I'm the one who behaved like a lovesick fool."

"No!" he immediately protested, lowering his hands from his face so that he could hold her hands, "No, you were being brave. It's cute. I'm sorry I never noticed."

She smiled and pulled one of her hands out of his, so he stroke his cheek.

"It's okay. I'm actually kind of relieved that you really just never noticed and that you weren't painfully aware and just…" she faltered for a second and broke eye contact with him, "just ignoring it or something. I mean, I started feeling really stupid there eventually. Like, what if it was me who wasn't taking the hint that you simply weren't interested? It's why I sorta gave up once we got to high school," she confessed, looking heartbroken at the thought.

"That's funny, because I think that's when I started to have a thing for you," He tilted her chin up, so he could look into her eyes again, "Trust me, if you had continued dropping hints, I would have noticed. Forget about hints, I would have jumped at even the smallest opening. You can't even imagine the crazy lengths I've been prepared to go - if you had dressed up as Cinderella last Halloween and even just accidentally lost a shoe, I would have turned Danville upside down in its entirety to find it and be your Prince Charming."

Finally, the sadness in her eyes lifted somewhat and she bit her lip to hold in a giggle.

"And if you even dropped the smallest of hints that you lost it on purpose for me to find, I don't even know what I would do. Something extreme probably, like build an army of Phinbots to look for it, while simultaneously putting every other teenage male in the vicinity to sleep so that none of them could find it before I did. Or kidnap you right then and there to make you an actual pair of glass slippers or something."

Isabella was now laughing outright. "I definitely would not have complained about free Phineas-and-Ferb-brand footwear," she joked, wrapping her arms around his neck and pulling him close.

"Say the word and you'll have a custom pair by dinnertime," he answered, heart pounding as he put his hands on her hips.

"Mmm, I think a kiss will do for now."

He did not need to be told twice. Before they could get distracted again (what did she mean when she said "everyone knew"?), he put a hand on her face, pulled her close and kissed her.

It was a long, slow kiss filled with longing and sweet affection, that spread thick liquid warmth all the way down to his toes. Her fingers were gently dancing along his sides, making his skin buzz and his head spin. He never wanted it to end.

He reluctantly pulled away when he remembered something important, but couldn't help but brush his lips against her once, twice more before pulling away entirely.

"Hm?" Isabella opened her eyes slowly. The dazed look on her face filled Phineas' with more pride than he would ever admit to anyone.

"I just thought of something. You're not going to go out with Dylan, right?" he asked.

"Of course not. Why would- oh right, the thing in English class. I turned him down, obviously. He wasn't even surprised. It's not like he doesn't know that I have feelings for you," she waved off casually, before leaning in to kiss him again, but he needed to get clarification on what she said first.

"Wait, wait, how would Dylan- and if he knew why would he-"

Isabella just shook her head, laughing. "I told you, everyone knows how I feel about you. Everyone."

"Everyone? I mean, I'm kind of offended that Ferb knew and never told me, but…did Buford? Baljeet?"

"Yes and yes."

"And I'm guessing the Fireside Girls, too?"

She took his hand and started tracing the lines of it with her index finger. "We haven't been Fireside Girls in a while, but sure, they all know."

His entire arm was tingling, but there was no way he was going to ask her to stop. "Who else?"

Isabella laughed. "Everyone you can think off, Phin."

"Candace?"

"Yep."

"Your mom?"

"Yes!"

"Oh my God, MY mom?"

"Oh yeah, she knew for sure."

"I must have looked like such a dip in front of everyone!" he complained.

"Aww," she cooed, climbing in his lap to hug him, "No, don't be embarrassed. You were just a little oblivious, a lot of boys are! Your head is always in the clouds. It's what allows you to be this amazing, creative, positive person I fell in love with. And don't you dare bash the boy I'm in love with, I kinda like him just the way he is."

Phineas blushed heavily. This was too much. He was going to explode in a billion tiny pieces. "I like you just the way you are, too."

"I'm glad," she said. They were about to kiss again, when he remembered something REALLY important.

"Wait, again, sorry, just one more thing-"

Isabella groaned. "Seriously? Is this going to be a thing where I try to kiss you and you stop me? Because I'm not a fan."

He had to laugh at that. "It won't be a thing, I promise. But just real quick - Isabella, will you be my girlfriend?"

She gasped. "Of course! I thought that one was a given with the whole declaration of love and all."

He shrugged sheepishly. "I have never done this before! I just wanted to make sure there were no misunderstandings."

"How very sensible of you," she mock-praised him, patting him on the cheek. He had no idea why he even found her irresistibly adorable when she was mocking him, "So, has every matter been discussed? We're officially boyfriend and girlfriend?" she asked.

"Oh, I don't know," he teased, "I'm sure I can find another thing to talk about, like, um-"

Isabella's bell-like laugh interrupted him. "Shut up, Phineas!" Then she grabbed him and pulled him in for a sweet, lingering kiss.

It took Phineas a long time before he came back to finish their history project.

Ferb could barely suppress a smirk when his brother sauntered back into their garage with the biggest grin on his face.

"Oh, shut up, you," Phineas said when he saw his brother's knowing smirk, but the big, happy smile on his face negated his words somewhat.

"For the record," Ferb announced, "I'm taking all the credit for this."

Next chapter: A small epilogue!

By the way, who else finds the official timeline kinda... off? 'Act your Age' was supposed to take place TEN years after the main series, right? But that would make Phineas, Ferb and the gang roughly eight years old? Which means that Vanessa would be eight years older than Ferb and 26 years old by the time Ferb is 18. And I know it's legal and everything, I just don't think that a 26-year-old, beautiful, mature Vanessa would go for a guy who literally just finished high school? But whatever. Besides, in the episode where the gang travels twenty years into the future, future Linda states that "her" Phineas and Ferb were thirty, which would make them ten. In my mind, they will always be ten (and Ferb eleven or almost eleven) in the main series! ;)