Disclaimer: I don't own Phineas, Ferb, Candace, Amanda, Isabella... well, that pretty much covers the important characters who are mentioned in this ficlet.

Author's Note: This is a relatively fluffy story. It also refers to Phineas and Candace being in a relationship with each other. If you are shocked by that, you should probably read the Author's Note I wrote for my other story, 'Fear, Loving and Secrets in the Tri-State Area'. Although these stories can be read separately they do fit into one continuity, so I would recommend reading 'The Shrunken Sister' (which is chronologically first) and FLS before reading this one.

For those readers who are familiar with this story already by having read them on my Archive of Our Own account, you may consider me uploading this story here a teaser for what is eventually meant to be a sequel to FLSITTSA, called Canswap and set a few years after this short story takes place. And since I'm running out of interesting things to say here, please read and review!

The Little Things That Changed

"MOOOOOM!"

The shrill voice in her ears was so unexpected and yet so familiar that it took Candace Flynn back to her youth for a moment until she realized that couldn't be it. For one thing, it would have to have been her screaming in those days, and she knew very well she hadn't opened her mouth. For another thing, her mother would be at her own home by now and couldn't be reached no matter how loud she yelled. Finally, there was the fact that the voice was much younger than her own thirty-three years of age would have justified.

It was definitely familiar, though, and as she turned her back to the dishes left by their evening dinner Phineas greeted her with a knowing grin, having left his newspaper behind on the couch and having walked over the moment after he heard the noise. "Now that takes me back" he said. "How long has it been since you tested your lungs like that?"

Candace rolled her eyes at him, even though she agreed with the thought. "There's got to be something real going on" she replied. "Amanda isn't usually that hyperactive."

A second cry proved that and Candace rushed up the stairs, her brother following only a few paces behind. A quick scan of the second floor revealed nothing, neither in her bedroom nor in Phineas', and the kids' bedrooms were downstairs. Which meant the scream had to have come from the attic.

Sure enough, that was where Amanda was, crouched over an old crate in a pose that immediately made Candace's maternal instincts assume the worst had happened. She rushed over, but couldn't see any marks on her daughter's body. That didn't necessarily have to mean anything, a potential bruise could very well have been under her clothes, but… "What's wrong, honey?"

Rather than answering, Amanda moved aside and let her see for herself. On top of the other stuff in the crate a scrapbook lay open, and Candace didn't need more than one glance at the picture on the opened page to make her heart nearly come to a stop. This wasn't just any photograph.

This was the photograph.

Curse you, Isabella Fletcher.

Of course it wasn't fair to put all the blame on Isabella for making these pictures. In fact, Candace knew very well that she only had herself to blame for putting them in a crate on the attic and forgetting about them. Who even kept a scrapbook around anyway, in this day and age? Digital technology had been all the hype when this picture was made, and it was even more so now. Which was probably the reason why she'd put this book in the crate – she had the pictures on a tightly-protected file somewhere anyway so she wouldn't need the actual photograph anymore. She didn't even know why she hadn't destroyed the thing right away – perhaps she'd intended to but forgotten about it, perhaps it was just too many painful experiences with evidence getting randomly erased just when you needed it in her youth. But for better or for worse, it was here now, and she had some explaining to do.

Nevertheless, old habits died hard, and thus her first instinct was to turn away and divert the blame. "You knew she might come up here" she hissed, probably loud enough for Amanda to hear her anyway. "Why didn't you do anything?"

Phineas shrugged. "It was always your scrapbook to begin with, and you know as well as I do that I don't have the best track record of keeping secrets – you were the one who had to teach me how to. If you wanted to keep this from your daughter's view you should have hidden it better."

He was so calm and laid-back about it, and this was definitely one of the moments when that trait was more annoying than endearing, especially because as much as she hated to admit it, he was entirely right. But she had to focus now. She snatched the scrapbook off the crate and quickly shut it.

Amanda looked up at her with that same shell-shocked yet grim look on her face. "I've already flipped through the rest of the pages."

By this age, Candace had learned to tell when her children were not telling the truth, and Amanda in particular was a lousy liar. (She got that from her father.) But this time, she could see no traces of bluff on her eldest's face. Which meant she was telling the truth, and she had seen all those other pictures as well. The dance, that surprisingly passionate kiss she got for her nineteenth birthday, the tunnel of love in the backyard, and all those other little moments in the early years of their relationship. But none of that photographic evidence was as obvious as the picture she'd initially seen, the one with them holding the baby in the hospital while Phineas was proudly showing the non-official birthday card, the one they hadn't dared to send to anyone but their closest friends.

Of course the card was vague enough on the picture that it could very easily be misread, especially the crucial part with the parents' names. That was why Candace had initially hoped that this was all Amanda had found, and she would be able to keep her daughter in the dark once more, to withhold from telling the story until she was older. But taken together with all of the other photographs, it painted a pretty clear picture.

Amanda blinked and turned away from her mother, having apparently expected some answer but realizing it was not forthcoming. Since there was someone else in the room, it didn't matter anyway.

"Uncle Phineas, are you my father?"

There, the question was out. And true to form, Phineas solemnly nodded right away. She wouldn't have expected anything else – there was a limit to the extent Phineas was willing to fool other people, especially his own children. But one part of her heart yet desperately hoped against hope they could be able to keep this from Amanda just a little while longer, and that part stung at Phineas' confirmation.

Their eight-year-old daughter just kept staring at them with those analytical eyes, and Candace suddenly realized she wasn't much younger than Phineas and Ferb had been when most of their experiments had been going on. True enough, she was already always telling Xavier to seize the day, and she was clearly ahead intellectually of other kids her age. Amanda was a real Flynn, one who wished to investigate and learn and break so many of the constraints that bound her because she was only a child. Perhaps it had been stupid of her mother to think they could keep this a secret in the first place.

"How could you do that?" she burst out, her voice near-identical to Candace's own at that age. "I mean, you and Mom are siblings! You can't just… have a child! That's impossible!"

"That's what you said when your Mom told you babies come from storks" Phineas said amusedly, sitting down next to her. Somehow, he always knew what to say to calm people down – it was one of the things she loved most about him. "And do you remember what I told you then?"

Amanda nodded. "You told me that I was both right and wrong, that babies on earth indeed didn't come from storks… but that that didn't mean it was impossible, because it's a big universe out there and you had met plenty of aliens yourself, so maybe it was possible that somewhere, babies were grown like crops and delivered by storks. There's a great deal of stuff possible, as long as you open your mind to it."

"That's right" Phineas replied, clearly pleased with her excellent memory. "So, would you agree with me that me and your Mom having you together is possible?"

"Well, technically so, but…"

"And would you agree to hear us out as we explain it to you?" Phineas put on a serious yet kind face. "That's all we're asking. I'm not asking you to consider this wrong or right – your Mom still freaks out about this every few months, and I'm definitely not mad at her for that."

"Not just about this" Candace sulked. "It's just that every time I leave Danville for some reason, I like getting a taste of normalcy. So I'm not just wondering about whether living with my brother is right, there's also all the incredible and absurd contraptions he builds." She glanced over at Phineas and smiled. "But it usually takes me just one hour with him to forget all of that and relish my life here again."

She got the expected blush, and leaned in to kiss him until she remembered Amanda was still watching.

Amanda, to whom they had to explain what was going on. Right.

When they really got the story going, Candace found it didn't actually take them that long to tell the whole tale of their relationship. They briefly covered how Phineas had gained a crush on her, the events of that crazy autumn in 2012, and then their blossoming relationship as time had passed. They gave a new perspective on the things that happened since then, uncovering to their daughter what had really been going on all those years.

She and Phineas had moved in together shortly after he had turned eighteen, first into an apartment on the outskirts of the city, but then their entire life had become a train-wreck when at age 24 Candace became pregnant. She and Phineas, who had still been only twenty at the time, had moved into a larger house and had used the cover story of an intense but brief romantic relationship with a guy who had dumped her before she could ever introduce him to anyone – with help from Ferb to answer any potential questions and cover up loose ends – which had gotten her a strong reprimand from their parents (especially from her mother), although not as much as the actual truth might have. That reprimand was repeated in full when the excuse became necessary again just three years later. But gradually, they had settled into this new life, with them living like an unusually close brother and sister and with, besides Stacy who had been living in Uruguay for years now, only Ferb and Isabella knowing the truth.

Well, until now.

Amanda blinked at them. "So that means that Uncle Phineas' bedroom…"

"Is mostly unused" Candace finished. "At least as far as the bed itself is concerned, since you know how much of his stuff he stashes in that room. Making too much noise isn't the only reason we never want you guys upstairs after we turn in for the night… but it's necessary to maintain appearances for visitors, not to mention that he likes lying down in that bed whenever he wants to think."

Amanda dully nodded. "But when we all think he's in there at night, he is really sleeping in your bed with you?"

"When he's not occupied at work until well after one in the morning" Candace replied, playfully sticking her tongue out at Phineas, who returned the gesture. "Seriously Phin, how many times do you and Ferb have to revolutionize the world with your company before you call it quits?"

"As many times as we can" Phineas said grinning. "That, Candy, is carpe diem. There are so many great things we can do, and there's so much to enjoy while doing it. Come on, you've always liked helping us out, even though you didn't want to admit it at first. And Ferb and I haven't had that many late nights at the office. Have you ever heard a single complaint about it from Isabella?"

"Just about once every week" Candace replied dryly, although she knew he could see she was exaggerating. "Just try to put a stop to it a little sooner in the future when you can, okay? You do have a family after all."

"Gotcha, sis" Phineas said, being probably the only person in the world who could deliver that sentence seriously in this context without even adding a mock salute.

Candace turned back to Amanda, and then realized something – this was the first time she and Phineas had been able to playfully bicker like a couple in front of any of the kids in years. It had been easy when Amanda had still been a baby, but as soon as she started growing up, they had had to keep the truth from their kids and make them believe the cover story the outside world believed – that they were a normal brother and sister who just happened to be living together for the time being. That didn't mean they couldn't still stretch the boundaries of that relationship – they probably would have given the children a very strange view of what uncles in general were like if not for the visits of Uncle Ferb – but there had always been a more hidden part that could only come out when they were alone or with Ferb and Isabella. It had never really seemed to matter before, but only now that they had been able to be themselves in front of Amanda did Candace realize how much that acting had bugged her.

Additionally, she could see in her daughter's eyes that this clearly spousal conversation had probably convinced her more than the entire story. She could see Amanda quivering, looking then at Phineas, then at her – nervous for some reason, but beginning to accept this.

"Mom?" she finally asked, her voice shaky.

"Yes, Amanda?" Candace replied curiously.

"Does – does this mean that I… that I, with Xavier… that we…"

Remarkably, Phineas picked up the meaning behind Amanda's words sooner than Candace did this time. He pulled his daughter onto his lap and she let him, because even though she had never known him as her father he had been her uncle, and her favorite one at that. "Mandy, you don't have to worry about anything" he said warmly. "That this happened to your Mom and I doesn't mean it'll happen to you and Xavier as well. And if it does, it won't be your fault, but I do hope you will tell us right away. Maybe just one of us if that makes you more comfortable. There's a chance of incestuous relationships like ours creating physically damaged children – not that there's anything wrong with you" he hastened to assure her. "I double-checked at the hospital when you were born. You're completely healthy, and I made sure we have the best care available for all of the kids in case something does go wrong. But the chances rise in cases of double incest, so that's one reason we'd like to know right away. Just so we can give you some parental advice on whether or not the risks outweigh the benefits." Candace good-naturedly rolled her eyes at this – Phineas still hadn't managed to lose his old habit of cheerfully telling the grimmest of stories, even when those weren't necessary at all. Their daughter hadn't asked anything about health hazards after all, and to bring them up now when the main truth about them was only just sinking in…

Fortunately, Amanda didn't seem all that perturbed by the tale. "But you guys never told Grandma and Grandpa, did you?"

"That's true," Candace admitted, "and to be honest we've been wondering ever since whether we can tell them one day. It would be hard to tell someone who's completely unaware that something like this is going on in their family, and that's why we hope you promise you won't tell anyone about this but Uncle Ferb and Aunt Isabella unless we say so. That includes your brother and your cousins." Amanda nodded, casting a look to the attic window from where they could just see Xavier playing in the sandbox outside. "But since we obviously do know about this happening in our family, we promise you we won't be mad if you and Xavier decide one day that you like each other. Just as long as you don't think you have to date your brother just because your Mom did the same thing – we'd be perfectly happy with you dating any boy you like, as long as you guys can have a stable, safe relationship and you're happy together."

The relief was obvious on Amanda's face. "Good. Because although I really like Xavier, thinking of him in that way is kinda gross. Not to mention that he's just a kid!"

Phineas and Candace both chuckled and shared a knowing look in reminiscence. "You never know" Phineas said, letting Amanda off his lap and standing up, which lead to Candace doing the same. "That's what your Mom thought about me when we were your ages, and look how that turned out."

Candace gave him a look. "Anyway, does this satisfy your questions for now?"

"I guess so" Amanda replied, as they walked out of the attic. "This is really a lot to take in, though. So does this mean I'm going to have to call Uncle Phineas 'Dad' now?"

Candace and Phineas both halted on their way down the stairs and looked at each other. "I-I hadn't really thought of that" Phineas admitted. "You can do whatever you want, I guess… although admittedly, I think I would really like being acknowledged as a father. I've wanted kids for a long time, and even though I've always known you guys were mine, I… it didn't feel…" His voice wavered. "Why don't you just think about it for a while, okay? That's got to be a big change, for you too."

Amanda nodded. "Definitely. I've got all these questions and I just know I'm going to have a lot more in a few hours, but I really have to study now. We have a big project for school due tomorrow."

Candace let out a 'tsk'. "And you're only saying that now, young lady? What were you even doing up in the attic anyway if you had to do school work?"

"It was a project on family history" Amanda replied. "Obviously I can't use this, though… I'll have to dig a little further."

"You'd better" Candace replied teasingly. "I don't want to get called into a teacher's conference to learn that the whole town knows our secret. On that note, please bury the scrapbook where you found it – I'd prefer to prevent this from happening again with Xavier in a few years." Even as she said it, she knew it would be pointless – her children were Flynns. They had too many of their father's genes not to investigate the world around them and dig to find the truth behind the mysteries they uncovered – Xavier would have to be told sooner rather than later, or he would find out by himself.

Amanda politely nodded. "If I have any further questions, should I just write them down then?"

"Actually," Phineas spoke up, "how about you come to us tonight after you're done with your work, sleep with us, and we'll fill you in on the details you might want to know? Xavier would be downstairs and asleep after all, so we can answer all your questions without having to worry much about anyone barging in. And yes, Candace, that does mean I wouldn't be going to the office again tonight. I have spent too much wasted time there already today, so I think I'd like turning in at 10 PM for a change."

Amanda blinked. "You want me to sleep in Mom's bed? With both of you?"

"Well, we used to do it all the time when you were little" Phineas said, blushing. "I guess now that you're not a little girl anymore, it might be a little strange…"

Amanda shook her head. "No, that's all right" she replied, putting one step on the staircase that would lead her back up into the attic. "I would really like some answers. See you at ten then, Mom… and Dad."

And from the emotion-filled pride she saw on Phineas' face at that last word, Candace suddenly knew that somehow, after tonight's revelations, their lives wouldn't be ruined or drastically altered forever. Often, a change in someone's life would be radical, and it would be feared for that. But occasionally, when you took that plunge into the unknown, it turned out that your life wasn't actually altered all that much, and the few parts of it that were all turned out all right. That had been true when Phineas first asked her to date him, and that was true today. It made her feel increasingly confident that after today, they were going to be an even happier family than they had been before.

THE END.