I do not own Phineas and Ferb.

Phineas leaned against the back of his door, breathing hard with his eyes wide in panic, before sliding down and collapsing into a heap at the bottom. Curling his knees up to his chest and running his fingers through his fiery red hair, he shook his head and sighed, clearly exasperated. Needless to say, it had not been a great night for the young inventor. He sat quietly, deep in thought, while mulling over the events of the last few hours. What on Earth was happening to him?

If Phineas was being honest with himself, the nervousness he had been feeling tonight had really started the last day before summer vacation. Phineas thought hard, hoping he could piece together some sort of idea as to what was going on. It had been an ordinary day (well, ordinary for him), until the end of the night. Isabella had complimented him. Then he had felt all sweaty and jittery. She had hugged him and it was… Nice. Warm and different, but good different. Phineas couldn't help the small smile from creeping across his face when he thought back to the embrace. He shook his head, trying to clear it. They had hugged and held hands numerous times when they were younger, so it shouldn't be a big deal. He didn't understand; why had it felt so different?

Okay, fast forward, Flynn, what happened next? Their first week of high school. Nothing had really happened that week, but maybe that was the problem. He had felt a bit subdued after Monday, why was that? You hadn't been able to see Isabella, Phineas, except briefly during lunch and English. Would it have anything to do with that? It was true, all week he had tried to push it away, but he had a nagging feeling that he had missed her.

But that's not so strange. She's one of your closest friends, of course you would miss her, Phineas reasoned. And inviting her over for the movie tonight, that was completely normal. We used to do that all the time during the summer! But? You were more excited than usual when she said yes, a small voice argued in the back of his mind. And then when you answered the door, you your stomach kept flip-flopping. Why were you so nervous?

The voice had a point. He was usually never nervous around Isabella. I mean, why would he be? She was his friend. She knew practically everything about him and vice versa. It's not like they had any secrets or reasons to feel jittery. But when he answered the door she had looked different. No, it was more than that. She looked pretty, Phineas finally admitted to himself. Was he allowed to think that? He always knew that she was cute, and he wasn't blind, over the years all of his friends, including him, had grown up physically. Yet Phineas blushed while realizing that maybe "cute" wasn't the right word to describe her anymore.

Next they were at dinner where his mom and her were talking about school, and suddenly Isabella said that she liked to hang out with him. His head had turned to mush and he couldn't speak properly. Later, he had tried to pay attention to the movie, he really had. It was Space Adventures! With deleted scenes and interviews with the cast! But all he could focus on was how soft Isabella's hair looked when the light from the TV shined on it. And how good she smelled. Like, lavender? Vanilla? Cinnamon? Had she always smelt this good? Ugh, he felt like his brain was about to explode.

Just walk through it slowly, like a math problem. Math was definitely something Phineas could handle. He could do this. Okay, so we we watching the movie... Isabella sat on Phineas' left with Ferb on her left. Everything had been fine, it had started out simply enough, but ten or so minutes into the movie, Isabella had changed her position on the couch. She brought her legs up sideways, sitting at an angle with her body facing Phineas. Phineas didn't think much of it, until he glanced over, suddenly noticing she was sitting a lot closer to him than he originally perceived. Had she moved over closer to him? No, that's silly, it's Isabella. She was probably just trying to get comfortable.

Either way, this new position was highly distracting to Phineas. Every move she made had him looking over at her. From the way she hugged her legs tighter when she got scared to the way she unconsciously played with her hair, twirling the black tresses between her absentminded fingers. Phineas didn't know why he all of a sudden found her so much more interesting, but he couldn't help but sneak looks at her every few minutes. Eventually, he was watching her more than the movie itself, and even worse, she caught him. She had felt his eyes on hers and looked over, smiling sweetly and shyly when she realized she had found him mid-stare. He had quickly looked away, trying to fight the goofy smile beginning to stretch over his face.

This was all too much, and that was what led him to suddenly stand up, saying that he felt sick and that he would see Isabella on Monday, before running to his and Ferb's room and collapsing at the bottom of his room's door. It was a lot to handle; certainly not his finest hour. Well, one thing is for certain, Phineas thought. All this nervousness is all leading back to Isabella.

He finally stood, unravelling himself from the pretzel shape he had somehow tangled himself into. "Okay, what's wrong? How do you usually handle problems, Phineas?" He murmured to himself, realizing he probably looked crazy, but honestly didn't care. These were stressful times! Ideas, planning, blueprints, those were what always came easily to him. He was the idea guy! Ready to seize the day, ready to solve whatever problem he or his friends encountered.

But this was different. He was beginning to feel worked up, nervous, and more excited than usual around his childhood best friend. He was confused, and maybe even a little scared. This was his best friend, this was Isabella. Yet he was stuck in a storm cloud of uncertainty and bewilderment at these new found reactions. But, it was also kind of sunny? Like when it's really dark and cloudy in one area of the sky but then another section is really bright and warm and clear? Phineas rolled his eyes, whoa, slow down with the metaphors, this isn't English class. But it was true, these new developments were confusing, yes, but also, maybe kind of… Nice?

He collapsed onto his bed, head first, allowing the fluffiness of the pillows and blankets to provide comfort. He heard a soft chattering to his right and propped himself up by the elbow, smiling weakly at the fuzzy companion. "Oh, there you are, Perry. I didn't hear you come in." Perry hopped onto the bed, nudging Phineas' arm and slipping under, simultaneously offering comfort while asking for some back rub love. Phineas willingly consented, his heart rate decreasing easily with each scratch on Perry's back. "When did things get so complicated, Perry?" He was provided no answer except for a soft growling noise, but Phineas didn't mind. What he did mind was that no matter how comforting his childhood pet was, not all thoughts could be erased, and one continued to linger on despite Perry's calming presence: What in the world are you doing to me, Isabella?

Meanwhile…

"Ferb, what the heck is going on?"

Blushing, stammering, catching her crush watching her; it had been an extremely eventful night for the young teenage girl, so Isabella turned to who else, but her crush's brother for help. She was looking at Ferb, vexed and a little shocked by the events of the last few hours while Ferb leaned back in his chair, glancing back at Isabella with an amused expression etched onto his usually blankly expressed face.

"I think we both know what is happening here, Isabella."

She shot him a look; she was not amused. "Ferb, come on, I cannot handle your sarcasm right now. I mean, this could be big. Do you think he's actually starting to, beginning to…"? She stopped, not even daring to say the words out loud.

"Well, he is certainly displaying some very clear indicators of crushing. Blushing, nervousness, an inability to form coherent sentences…"

Ferb was smirking, laughing at Isabella's shock and Phineas' complete lack of understanding of his own feelings. Ferb loved Phineas like, well, like a brother, but it had been pretty amusing to watch this inner struggle go down.

"Ferb, are you going to be real with me or what? Does he like me? Should I talk to him? I don't want to scare him. Or what if he secretly hates me? This is so surreal." She was biting her lip and tugging at the hem of her shorts, a habit that always seemed to emerge when she was nervous. Which also happened to coincide with many moments involving Phineas.

Ferb sighed, realizing it was time to put the amusement to rest and be serious. "Isabella, I honestly do believe that Phineas is starting to develop feelings for you. Does he understand what those feelings are yet? That, I am not so sure of. I will talk to him when he's ready, and help the best I can. This is obviously all new to him though, so it may take some time." Ferb looked at her, hoping she had taken it all in and that he wouldn't have to repeat himself. Though he had talked more and more over the years, he still found that unnecessary dialogue, was well, unnecessary, and tried his best to avoid it. Although he couldn't help but add, "And Isabella, don't be daft. Phineas would obviously never hate you."

She had stayed silent during his lengthy spiel, but finally laughed. "Okay, okay, I will take your word for it and be patient. Ahh I can't believe this may actually be happening!" She squealed excitedly, bouncing up and down on the living room couch, not able to contain herself. Then she remembered the end of his speech and shot him a glare, "And Ferb! Don't call me daft, god."

Ferb rolled his eyes and chuckled good-naturedly. "Well, someone has to talk honestly around here. And without all that stammering."

Isabella let out a melodramatic sigh and stood, shoving him a little on her way to the front door. "Have you always been this snarky? Because you're taking it to a whole new level. But thanks, Ferb. I'll see you Monday at school. And don't forget to give me updates. Every hour, Fletcher!" She called out behind her as she slipped out the front door.

Ferb snickered, then collected the DVD, heaving a big sigh in preparation for the necessary and impending talk with his brother. This will certainly be an interesting conversation, Ferb thought. But it is most definitely about time, he concluded as he climbed the stairs to his and his brother's shared room, pondering along the way as to what was to come.

Thank you all so much for your follows, favorites, and reviews! I hope you like this chapter. I know not much actually happens plot-wise, but I thought it was time to see how Phineas is processing all these new found feelings, and whether or not he could even understand them. Plus, it was definitely fun to write the banter between Ferb and Isabella. I tried to make it sarcastic and close/sibling-y, hopefully with a bit of humor thrown in. Anyways, I hope you all enjoyed.