Disclaimer: I don't own Phineas and Ferb, or its characters, or the song "Let it Snow."

I wrote this last September, but it was a little early for Christmas fanfics, so I waited until now to submit it. PhineasxIsabella, obviously, and that's the only pairing. This is set mid-December, they're both 15, not a couple in the beginning, and it's set in winter break. The inspiration came from me listening to Let It Snow, the P&F one where Isabella's singing. Enjoy!

Isabella sighed and wrapped her scarf around her neck, preparing to leave to walk home. Phineas had invited her over while everyone else was out for the night. School had just let out two days before, and Christmas was coming closer and closer. But Isabella wasn't too confident that her Christmas wish would come true. It never had before.

"It's getting heavier," said Phineas from where he was peering out the window. Isabella knew her was referring to the snow, which had been falling ever since she had arrived. A few years ago it never would have been a problem, but Isabella and her mother had moved farther away. Still within walking distance, but they weren't right across the street anymore.

"Don't worry, I'll be fine," she replied, sliding on her gloves. It was dark out as well, but she knew the way home, so she was certain that she would be fine.

"I don't know Isabella, maybe you should call your mom to get a ride," worried Phineas, moving away from the window and walking over to her. She thought it was sweet how worried he was about her, but it was just snow.

"It's only a few blocks; I'll be perfectly fine. I'll call you when I get home if it'd make you feel better."

"Alright," conceded Phineas. "If you're sure that you'll be fine."

Isabella smiled and put her hand on the doorknob.

"I'll see you tomorrow Phineas," she said, and then went to open the door, but was hit by a sudden blast of wind so strong and cold, that the two of them had to fight to close the door. When they did, they both ran to the window and opened the curtains, seeing that the storm was getting worse. There was no way that Isabella would be able to walk home in it.

"Maybe I should call my mom," said Isabella, and walked over to get the phone. She dialed the number, and her mother picked it up on the second ring.

"Hey mom, do you think you could come get me?" asked Isabella. "The storm's getting worse."

Isabella heard a burst of static on the other end, and when her mother spoke, her voice was cracking over the phone.

"Storm- too bad- stay there- tomorrow- see you-"

Suddenly the lights went out and the phone disconnected. The power had gone out because of the storm. Phineas stumbled around in the dark until he found a flashlight. He flicked it on and made his way over to Isabella.

"There's no way anyone's going out in that," he said, leading them over to the couch. "Looks like you're staying here for the night."

Isabella couldn't help but feel happy at that. Phineas walked over to the fireplace and within a minute he had a small fire going. The fire's dim glow lit the room, and Phineas turned off the flashlight. He then walked over to Isabella and took her hand. She blushed as the two of them walked over to sit in front of the fire.

"The weather outside sure is getting worse," said Phineas.

"But the fire's so nice," said Isabella. "It's not too bad really."

Isabella moved herself slightly closer to him, taking this opportunity to flirt as she always did.

"You know Phineas," she started, still blushing slightly, "your parents probably won't be home either, so it'll just be the two of us for a while."

Phineas nodded, staring at the fire.

"Yeah, it's too bad about the storm," he said, and Isabella suppressed a sigh. Obviously she'd have to try a little harder.

"Hmm, it's still kind of cold in here," she said, feigning a shiver. Phineas smiled and put his arm around her, which almost made her faint.

"Better?" he asked.

"Much," she managed to get out. The two of them sat there for a few more minutes, not moving or saying anything. After a while it started to get kind of hot for Isabella, because she still had her coat on, so she quickly stood up and took her things off until she only had her jeans and long-sleeve on. She sat back down, and edged herself up closer to Phineas.

"I could always dig up our old power generator from the basement and see if it still works," offered Phineas. "If it does, it'd give us light."

"No, that's fine, I like it like this," answered Isabella. She slowly leaned her head down and rested it on Phineas' shoulder. He was surprised by this, but he let her do it, and found himself even liking it.

"Umm, Isabella?" he said, his thoughts racing.

"Yes, Phineas?" she replied innocently. Phineas turned his head slightly to look at her. He felt himself experiencing feelings he seldom had before.

Has Isabella always been this pretty? He thought. Don't be stupid Phineas, of course she has.

He couldn't think of anything to say to her, so he stayed quiet. Isabella smiled slightly. So far, he was reacting well. She slid her hand over the hardwood floor and rested it on top of his. Phineas hesitated for a second, and then turned his hand over and held hers in it. Isabella closed her eyes and smiled wider. The light of the fire flickered gently, giving the room a mystical feel to it. Phineas felt his heart racing at Isabella's touch. It was strange, because of course he had held her hand before. So why now was he suddenly feeling like it meant something else?

Isabella was perfectly content to stay that way for the rest of the night, but she knew that Phineas was new to it all, so she decided to lay off a little and let him go at his own pace.

"It doesn't seem like the storm's going to stop anytime soon," she said, lifting her head up to look at him. Phineas nodded slightly, avoiding her gaze.

"Hey, I just remembered that Ferb and I built a battery powered popcorn machine last year," he said. "I could make us some."

Isabella nodded, and slowly slid her hand out from his.

"That would be great," she agreed. Phineas stood up and started towards the kitchen.

"I'll only be a few minutes," he said, and walked into the kitchen. Isabella sighed in bliss. Although he was obviously hesitant, the fact that he hadn't stopped her from holding his hand or resting her head on his shoulder meant a lot to her in itself. She knew that he had deeper feelings for her; Phineas just needed to realize it.

While Phineas watched over the popcorn, he kept glancing towards the living room where Isabella was waiting. There was something about the way that the fire's glow lit up her face, and made her eyes sparkle that made his heart beat so fast he was sure it could be heard from across the house. He didn't know why he suddenly saw Isabella differently. Or maybe he was just finally realizing how he felt.

Do I really have any more feelings for Isabella? I mean, she's smart, pretty, and she's my best friend.

Phineas sighed. Things like that were always so complicated for him. Even something as simple as holding Isabella's hand made his heart race. Thinking back on it, he realized that it always had, but he had ignored it. Maybe if he just paid a little closer attention from now on…

Isabella looked up when Phineas walked back in and sat down next to her again. He placed the bowl of popcorn on the floor in front of them and stared into the fire. He noticed Isabella watching him out of the corner of his eye, and blushed. She saw it, but then again, it could have simply been from the heat of the fire. But she liked to think that it meant something else.

They two of them sat mostly in silence for the next five minutes, occasionally reaching for a handful of popcorn. They had no idea what time it was, nor did either of them want to have to get up to check.

"This is nice," said Isabella softly. Phineas found himself unable to speak, so he just nodded. Isabella smiled and leaned her head down again to rest on his shoulder. This time, he reached his hand over to hers and held it. Isabella couldn't explain how happy she was that he had done that.

It was if something unspoken had passed between them in that single moment. They both found themselves thinking about the exact same thing, and Isabella lifted her head, turning to face Phineas. He turned to face her as well, and, not needing to speak, both knew exactly what was about to happen.

Without a word, they leaned towards each other, and the second their lips met, it was as if there were a million fireworks going off between them. It felt like years, but in actuality it only lasted a few seconds. When they pulled away, Phineas was speechless again, and Isabella couldn't stop the smile from spreading across her face.

"I love you, Phineas," she whispered. And that was all it took for Phineas to realize exactly how he felt.

"I love you too, Isabella," he replied, just as softly. He heard her quiet tinkling laugh, and saw her eyes sparkle.

"So you don't mind that you'll be stuck here all night?" he asked. Isabella smiled, and wrapped her arms around his neck.

"As long as you love me," she whispered. "Let it snow."

And she pulled him towards her, their lips locking into a kiss that meant more to both of them than they could have ever hoped for.

Just to clarify, this wasn't exactly a songfic. Some of it was, obviously, but it wasn't strictly one. So, what did you think?