"I wonder how you knew I was going to give you exactly that. Piper, why did you have to make it weird? You're harming everyone by pointing that out. Like, you and Jason are also related." "Very distantly. We're only" she was silent for a few seconds. "We're half cousins once removed. That's actually less far away than I thought and barely further than you and Percy. However, if we go by time since the last common ancestor which is a way better method for determining that (" I agreed with that last half sentence right away so it had probably been charm speak ") I come of way better with Ouranos having been dead for thousands of years" "well, the last common ancestor of Annabeth and me was Kronos and he's also been dead for thousands of years, not that much shorter than Ouranos probably" "Wasn't Kronos alive just over a year ago?" "Why are you so desperately trying to make it look like Jiper is less inbred than Percabeth?" "It's probably a combination of defending my original point and defending myself. How about we just agree that gods don't have DNA so dating our cousins is fine?"
"Sounds like a great idea" Annabeth said. "However, I wouldn't say that the gods don't have DNA, it's probably just a lack of recessive mutations and lethal-" "No one asked"
Just in case you didn't ask and the next part gets too boring, I'll tell you when it's over
"lethal factors. A lethal factor is a gene which, if present homozygous will kill its carrier before they are born. If it is present heterozygous it will either decrease the carrier's fitness, in which case it is considered dominant, or do nothing, making it a recessive lethal factor. A recessive mutation is similar except it just decreases your fitness if present homozygous but it usually doesn't kill you, at least not before you're born. If it did, it would be considered a lethal factor. I guess those are just the most extreme cases of bad recessive mutations. Or bad mutations in general. Well, if a trait was a lethal factor and also dominant, which by the way is not the same as a dominant lethal factor, it would kill all carriers and go extinct within one generation, so they have to be recessive mutations. By the way, not all mutations are bad, but most of them are so for the sake of argument we'll be assuming that they all are. With those definitions out of the way, I can get to part two of my presentation: why incest is usually bad. Suppose a recessive and disadvantageous mutation is carried by .1% of the population. When two people meet and have children then there is a. 1% chance that the father- by the way, we will be assuming non-intersex binary cis people here with no mythologically supported births, meaning that a child comes from a man and a woman. That's of course not always true, but it makes the explanation easier without getting me canceled- has the trait and the same is true for the mother. These two now produce gametes. Because gametes have a haploid set of chromosomes, each gamete has a. 05% chance of carrying the mutation. When they fuse, that adds up to a total change of .1% that the fetus has the mutation once and- wait, I just had someone tell me that that's not how you add probabilities and they are of course right. The chance is not .1% but rather .099975% but for the sake of easiness we'll say it's .1%. But just inheriting the gene once doesn't do anything, you have to get it from your mom and your dad in order for it to show effect. The probability for that is. 05% squared or .000205%. No, I meant. .000052%. That was wrong again. It's .000025. That number was so long that my dyslexia was kicking in. So, the chance of the child being disabled- assuming the mutation causes a disability- is 1 in four million. In case you're wondering, those four million consist of a one in a million chance that a given couple is capable of having a disabled child and even if that is the case there is only a one in four chance per child that it will happen. But that is only the case when the parents are not related. When they are related, the math becomes more complicated. Let's assume a boy who carries the mutation. The chance for this is one in a thousand. Now let's say he has a sister. Because he is a carrier, we know one of his parents has the mutation. The chance that said parent gave their mutation to the sister is fifty percent. There is also the possibility that both parents have the mutation, in which case there is even a seventy five percent chance. However, the chance of two parents having the mutation is significantly smaller so the chance of the sister having it only goes up from 50% to 50.075%. Actually, I need to multiply the fifty percent by the chance that exactly one parent has the mutation which is 'only' 99.9%, so it's actually just 50.025%, not. 075. We'll just call it 50% because my perfectionism can actually handle stating things incorrectly as long as I acknowledge that they are incorrect. So, if this boy were to have a child…" It might have been my imagination, but Annabeth might have looked at in a certain way during those last two words. "…With his sister, they'd have a 50% chance of being able to have a disabled child. Now we multiply that with the 25% per child from earlier and the. 1% change that the boy carries the mutation in the first place and we get a one in eight thousand chance per child that the child of a sibling couple will be disabled. That might not sound very likely, but it's still five hundred times more likely than without incest. With cousins, the math becomes a bit more complicated. Do you want me to explain it or just tell you the result?" "I don't really care about it" I said. "But that guy over there seems to be listening and maybe he'd be disappointed." "If you say so. Well, I enjoy talking about it so here it goes. We can again assume a couple. His dad and her mom are siblings. Like last time, we'll assume the younger boy, let's call him Mark, carries the mutation. There is now a fifty percent chance that he got it from his dad. We'll call him Michael. If this is the case- intermission, the chance that mark got the mutation from his dad is actually 50.05% but once again we'll round it down- we can use the same math as before to determine that Michael's sister has the mutation is 50.025%, again we'll round. The chance of the sister passing her mutation on to her daughter is also fifty percent. This means that Mark's cousin/girlfriend has a one in eight chance to have the mutation if he has it. If we combine all these probabilities, we find a one in eight thousand chance that Mark and his cousin/girlfriend can have a disabled child and a total chance of one in 32000 chance per child of it actually happening. That's a bit less likely than with siblings but still 125 times more likely than with unrelated partners. We can now proceed to part three: why demigods are fine. This is where I begin making assumptions. Actually just one assumption: gods do not carry mutations. More specifically: the protogenoi did not carry mutations and in the five or so godly generations that happened since then no one mutated. Therefore, all the gods are safe. Well, Mr. D isn't because his mother, Semele, was a demigod so he has some mortal genes. By the way, Piper, she was also your half niece. Do what you want with that knowledge. Circling back to our original topic, let's assume Michael and his sister, let's call her Martha are gods. Now the probability that Mark has his mutation from his dad is zero. Also, the chance that Mark has it at all is halved because only his mom could have given it to him. The same thing applies to Martha's daughter. These two now have a one in four million chance of being able to have a disabled child and a one in sixteen million chance per child of it actually happening. That's four times less likely than for an unrelated mortal couple. Therefore, demigods dating other demigods is completely fine. As long as they are only related on the godly side. Alcmene for example has a not okay family tree. Her father is a son of Perseus, her mother is a daughter of Perseus' other son. Both are descended from Andromeda, Perseus' wife, so they have almost the same problem as a mortal incest couple. But as long as the mortal ancestors aren't the same, everything is fine. That was science hour with Annabeth, now let's get back to enjoying the day."
It's over.
"That is an excellent idea" I said. "And we can start like this" I pushed Annabeth back into the water. Fine, it was a bit mean but Annabeth didn't mind it (Also, the water wasn't very deep right at the shore so she was back out in like two seconds). Or maybe she did and it was just her trauma around repressed opinions acting up. I assumed the former. I've known Annabeth for so long that I could tell when a yes meant 'yes' and when it meant. 'No, but it's not like people care so I'll pretend yes'. To my trained eye, said pretending wasn't perfect. Often it was just a tiny bit of visible disappointment after realizing that people's ideas didn't match what she wanted. In these situations, I always encouraged her to speak her mind and make her opinion known. And it was working, Annabeth was hiding her own will less and less, meaning that she was recovering from that trauma. This kind of trauma was, by some metrics, easier to deal with than the other, flashback causing type. Firstly, you could just talk about without, well, flashbacks happening. Basically all you needed to do was counteract the trauma-induced insecurities with positive affirmations. If handling regular trauma was like getting rid of a bomb by disassembling it piece by piece (except you actually had no idea how bombs worked and just had to do your best and actually you weren't really getting rid of the bomb, just trying to minimize the damage when it explodes and of course it was a magical bomb that regenerated after exploding), this was like getting rid of some sort of non-explosive machine using only sandpaper. It's safer, but it also takes very long.
"So guys, what's next?" I asked. "Wanna go back to the water?" "Why not? I think I'm stable enough. How much mental stability is even needed to go swimming? I guess I should be stable enough to keep swimming and not drown or at least make it to the shore in time. But other than that, water isn't a high risk area. It can actually be very calming because I feel closer to Percy" "Aww, my shipper heart. But where are you gonna get swimming clothes?" "I don't really need them. The only way that they're different from normal clothes is that they dry faster, but everything I touch already dries instantly anyways, so it makes no real difference to me. So, what are you waiting for?" Together, we ran to the lake and jumped in. For a moment, I considering pulling off another underwater kiss, but decided against it. I didn't want to make the others feel jealous of our relationship. At some point I felt someone splashing water at my face. I turned to the side and saw Piper at a very suspicious spot. "I sure hope for you that that was an accident" "Uh, no it wasn't" "You just challenged the son of Poseidon to a water fight. Prepare to die in a strictly metaphorical sense. Prepare to lose." I had a feeling that Annabeth wouldn't approve of this, so I ignored her. Piper had splashed some water at my face, I replied by having a wave crash over her head. "Is that all you can do?" she asked. "Are you sure you've processed all the alcohol from yesterday evening?" "Probably. On the other hand, the alcohol content in your blood only goes down by like 0.01% per hour and I didn't stop drinking until very late so there might be a small bit of remaining alcohol. So to repeat my question is that everything you can do?" "Not even remotely" Shortly after, Piper, Annabeth (who had quite literally been pulled into it) and I were part of a slightly unfair but very epic water fight. I of course made sure to not hurt anyone, partially because that's basic decency and partially because I didn't want to remind Annabeth (or myself for that matter) of my fight with Achlys. I considered this one of her worst traumatic events, but that was probably just my own opinion affected by the fact that I had caused it. On the other hand, this event had probably been bad for her trust in me which was kind of relevant for her healing, which made this a very significant bit of trauma. After a while, Annabeth declared me the winner which wasn't too surprising. I was already supreme lord of the bathroom and this wasn't that much different. Once we were finished, Annabeth and I left the water. "Uh, Percy, I forgot to bring a towel, so could you…" "No problem" one tap on the shoulder and she was dry. "Wait, you forgot something?" "Well, the idea that you can just do what you just did is burnt into my brain so deeply that I didn't even consider that you wouldn't be here today and that I'd need a towel. Only when I left the water I fully realized that you weren't there which I think ended up being the trigger for the flashback." "Well, I'm here now. So, what's next?" "How about just chilling?" I agreed. We sat down in the grass, hand and hand, Annabeth's head on my shoulder. We sat there for a while, just silently enjoying each other's presence. Knowing her by my side made me feel secure and relaxed like pretty much nothing else and I knew I had the same effect, if not stronger, on Annabeth. After a few minutes, I think I even heard a (extremely cute little) yawn coming from her. "Is it theoretically possible that you're maybe a bit tired?" "Maybe a bit. I didn't sleep too well those last two nights. Last night I obviously got to bed really late because of the party. I don't remember the end of it, but I probably didn't get into bed before two or so. And the night before there was this fire alarm in our room. It didn't go of or anything, but it had this little red lamp and at night it was the only light source. Not ideal for someone like me. And the nights before weren't must better; last one with you, first without, in a tent surrounded by strangers… That's why I'm" Another yawn "a bit tired right now" "Well, that's a problem you can solve. I'll be right back." I ran to where Annabeth had taken her clothes off. I grabbed her jacket and went back to her. I compacted the jacket into a bundle and put that in my lap. "The pillow delivery service has arrived" I announced. "Good, because in the long run, your shoulder isn't the best head rest." She laid down, her head in my lap. "This is better" I ran my fingers through her hair, or at least I tried, but it was too messy and I got stuck within seconds. "So, how's it going?" I asked. "It's alright. I'm with you right now, that's always a plus. I've mostly recovered from my flashback. So all in all…" She stopped talking for a few seconds and I could see she had trouble keeping her eyes open. "It's okay, if you're tired you can sleep if you want. I'll protect you." I drew riptide and slashed the air a couple of times" "Fine, maybe I'll go to sleep. Just for a few minutes" I had no idea what had made her so tired so suddenly, but hey, the way she was sleeping on my lap was cute as Hades( don't tell her I said that) so I didn't complain. The waves of cuteness appreciation coming from me were apparently enough to get Piper's attention as she showed up after a few minutes. "So, what love causing things are you two up to?" She asked. "Not so loud, Annabeth just fell asleep." "Aww, that's so cute. I need a picture" She pulled out her phone and took a photo of us. "Since when do you have a phone?" "I've had it for years, but I always kept it in my cabin until recently when I figured out I could just have it on airplane mode and be safe from monsters. If you ever need to blackmail Annabeth, I have something you can use" She showed me the picture. "Why the Hades would I blackmail my girlfriend? We trust each other. If I can't get something from her by asking nicely, I simply won't get it." "That seems like a thing people in healthy relationships do. But just in case, I have the photo. But just look at her. She seems so peaceful and just really really cute." "You know the rule that someone is either cute or hot? She's apparently too tired to care about rules." "Agreed." "Hey, she's my girlfriend" "So? I can still call her attractive." "You're right. That's kind of a possessive attitude and if I keep that going, Annabeth might wake up just to call me a sexist much. And then she'll be upset with me and no one wants that."
So, there you have it. A cute Percabeth moment. What more can you ask for (except for the chapter being on time)?