Disclaimer: I DON'T OWN PERCY JACKSON OR ANY OTHER FAMILIAR CHARACTERS. I ONLY OWN THIS STORYLINE.

Warnings: rated T for sexual references and a few swear words :)

Authors Notes: Because jealous!Annabeth is important and so is Piper/Annabeth friendship and just... this was born during a period of sleep deprivation. Forgive me.

THE HANDBOOK OF LOVE (WAS WRITTEN IN INVISIBLE INK)

It's hard to find the patience to tutor Percy. The thing is, he's not stupid, Annabeth knows, and she admits that he has ADHD and Dyslexia and the only reason why she overcomes it so easily is that she's Athena's kid. So she tries not to be frustrated with him. He's straight C's and D's and she'd once told herself that she'd never fall for someone like that but she loves him so much that she just doesn't care.

So, she reasons, it must be the frustration build up that causes her to snap. Today is one of the worst days. His mind is more elsewhere than usual, and his impatient tapping of his pen and his furious scribbling on the paper when he can't get the right answer is worse than it usually is. And he has a hard scowl on his face that Annabeth hasn't seen for a while. Not since... she can't even remember - but it brings back memories of the Giant War that she'd rather not revisit, so she decides not remembering is okay with her.

She looks over his shoulder at the sum he's attempting. He's already messed it up without even being halfway through and it's the most basic step that he's messed up on, too. And she doesn't mean to say it but it slips out before she can stop herself: "Wrong again, Seaweed Brain. Honestly, this is getting frustrating - don't be an idiot, I've already explained that bit a thousand times, I-" she stops as her brain catches up to her mouth (odd, since it's usually the other way around).

He stops tapping his pen and is uncharacteristically still for a long moment, like Medusa herself had turned him to stone with a mere glance.

"Oh, gods, Percy, I'm sorry. I just-"

"It's fine," he cuts in, sharply. He stands up from his position, where he'd been lying on his belly across his bed. His brow creases slightly. "I think we could both do with a break."

"Good idea," says Annabeth, trying not to flinch at the tense tone in his voice. "Maybe your mum finished baking those cookies, huh?" she hopes her voice sounds light and airy, but she's scared that it sounds too forcefully cheery.

She feels horrible. And maybe it wasn't that bad, but she'd hate it if someone else insulted her intelligence, and she knows that Percy is slightly insecure about the difference in their grades. Not that they should mean anything. Grades and intelligence are different things - because he's pretty much (not quite, but almost) on par with her in everyday smarts, even if he's too hyperactive to focus on numbers and too dyslexic to hand up a polished English essay on time.

But they head downstairs anyway, to where Sally is carefully taking some bright blue choc-chip cookies from the oven. Her hair is up in a messy bun, and she's wearing a grey apron and a light blue dress underneath. She's radiant, as usual, and Annabeth knows that her boyfriend doesn't only get his looks from his father. Her pregnancy has done nothing but make her look motherlier, and she's glowing with only two months to go.

Sally places the cookies on top of the oven and then turns around, a thick tea towel in her hand and a broad smile on her face that falters slightly when she catches the look on her son's face. "Hey, Percy, honey, are you okay?"

"Fine," he says, shortly, and when his mum begins to speak again, his gaze hardens and he reiterates: "I said, I'm fine." Immediately, he bites his lip and Annabeth knows that he feels bad straightaway. "Oh, gods, mum... I'm sorry. I just... I need some air."

And he runs a hand through his hair and heads out of the apartment before either of them can stop him.

Sally lets out a heavy sigh and leans back into the countertop. "He woke up screaming again last night," she says softly, and Annabeth snaps her head around to face her in alarm. "We'd made it a few weeks now and I... well I thought... it doesn't matter. But I woke him up and he kept telling me that he'd killed you... and it took me about ten minutes to convince him that he was safe and you were safe and I... I've never..." tears sparkle in her eyes, she looks down.

Suddenly, Annabeth realises why Sally was so adamant that she, Annabeth, come visit them today. And she knows now why Percy had been so upset at her insult. He'd already been on edge. She wishes she'd known earlier: it explains why he'd been so especially distracted today.

Now, when Sally sighs resignedly and offers Annabeth a cookie with a forced smile, all Annabeth has on her mind is Percy. She feels so horrible that she waits until he comes back, hugs him gently and pecks him on the cheek and announces that it's time for her to leave.

She IM's him every day, as usual. He's not upset about it still, not visibly, and so she hopes that he's forgiven her. She doesn't try to bring it up again, and she hopes he knows that she didn't mean it.

But this time, a week later, Annabeth remembers he's got his math test in a couple of days because he'd painstakingly mentioned it before she'd snapped at him last time. And so, she tentatively offers to tutor him again.

"Nah," he says. "Don't worry about it. You shouldn't have to... anyway, I got myself a tutor. She graduated last year and she's pretty good. I pay her about thirty bucks for an hour."

"You... have a tutor?" Annabeth says slowly, and tries not to think about the girl being only a year older than them, and she's probably attractive, knowing Annabeth's luck.

Percy smiles. "Yeah, Wise Girl. It's great. She's helped me out a couple of times so far and it's really helping. I think I might pass!"

Which is stupid, because it should be Annabeth helping him pass.

"That's great, Percy." she says dully, and hopes he doesn't notice how much she wants to find his tutor and slap her across the face.

As she usually does when she has the rare Percy Problem, Annabeth Iris Messages Piper. Piper might not be a very stereotypical Aphrodite girl but, whether she wants to admit it or not, when it comes to love she generally knows what she's going on about (unless Jason is involved, in which case she's utterly useless). And she's pretty good at figuring out Percy.

Which is weird, because that boy is anything but what Annabeth would call predictable.

Piper answers the IM with a sleepy mass of bed hair and half closed eyes. She's wearing a pink My Little Pony shirt that's almost three sizes too big, and one sleeve hangs down so low that Annabeth can see her white bra strap peeking through. But it looks damn comfortable, so Annabeth will give her that at least.

"Hey," says Piper. She's so tired she sounds almost drunk. "What can I do for you?"

The look on Annabeth's face is as deadpan as they get and Piper smiles. Annabeth is so not impressed.

"You know it's almost one o'clock in the afternoon, right? How are you still asleep?"

"Not anymore, I'm not," says Piper, and she smiles mysteriously as she pulls her hair out of its messy bun and let's it fall in a way that makes Annabeth resentful of her own curls (how does it fall perfectly without her brushing it like that?). "What do y' want, Little Einstein?"

Piper's limitless nicknames know no bounds and Annabeth curses Leo to Hades for his bad influence.

"Percy's mad at me."

"Is it actually your fault?"

"I think so?" Piper would know better than she would, even though Annabeth's pretty sure that she's mostly in the wrong. "Well, actually, I don't think he's mad at me anymore."

Piper looks at Annabeth from under half closed lids in the most disappointed way possible. "So why the Hephaestus did you wake me up then?"

"It's almost one o'clock! Why the fuck, were you still sleeping, anyway?" Annabeth's tone is incredulous, but she really shouldn't be surprised. Piper is always unreasonable when she's tired.

"Jason kept me up."

Which only reminds Annabeth that she hadn't had sex in the past month and fuels her irritation.

Annabeth wrinkles her nose. "TMI, thanks."

Piper looks amused, and she shifts so that she's sitting cross legged on her bed. Annabeth can see her grey track pants peeking out from under her absurdly large shirt. "Nah, not like that. We played Uno for, like, three hours straight."

"Right," Annabeth mutters. She's honestly not even surprised. "Well, anyway. I might've told Percy that he was an idiot when he got a maths sum wrong and now he's gone and got himself a tutor and I'm slightly jealous because she's only a year older than us and she's probably hot, knowing my luck."

Piper winces, and it takes her a few moments to even formulate a single word. "Okay," she says, slowly. "You fucked up. But, have they had lessons yet?"

"Like, a couple of them I think? And apparently she's 'really helping' him."

The look on Annabeth's face is irritated and stony. Piper grins at the sight.

"Watch out," Piper says, her voice dripping with sarcasm. She sounds more awake now, at least, and her eyes are wide and shining mischievously. "This dude turned down immortality for you, but he's gonna cheat on you anyway with his hot math nerd tutor."

"I was his hot math nerd tutor!" Annabeth says, ignoring how conceited that sounds in her furious indignation.

Piper shrugs. "I don't think you need to worry," she's being surprisingly unhelpful today. "He loves you a lot. And thinks you're hot. If he didn't, he never would've had his head between your-"

"PIPER MCLEAN!" Annabeth yelps in horror. "Holy Hephaestus. I might as well go and ask Clarisse for her advice."

Clarisse is surprisingly helpful in a 'give him hell for me' kind of way. And she's got a hidden soft spot for Annabeth, so that's cool.

"Your funeral, smart ass," Piper says coolly. Which only reminds Annabeth that, while Piper's been hanging out with Leo too often, she's become far too close to Rachel Elizabeth Dare far too quickly. The mannerisms are beginning to become too similar for comfort. "I'm just saying. Let him have his tutor and dedicate your time with him for more fun things. Like the aforementioned activity that you don't like me mentioning for some reason."

"I'm literally never talking about my sex life in front of you again. Ever."

Two days later, Annabeth meets the hot math nerd tutor. And she is hot. Annabeth is furious at the sight. She's a redhead, like Rachel, and the fact that her boyfriend once had a thing for Rachel isn't helping her nerves. She's furious, even though she knows she should really give Percy more credit. The guy is in love with her, she knows, so why can't she just relax?

Fucking hell in a handbasket.

His tutor is laughing at something he's said while twisting her hair into a messy bun. Then, she rolls her eyes and leans forward to point at something on his page, while he flushes a pale shade of red and quickly scribbles whatever it was out and rewrites it.

"Well done," she says, cheerily. "That's better. But, can you see why that was wrong?"

"Yeah," he says. "It was a stupid mistake."

"It was an honest mistake," she corrects him. "Don't be so down on yourse… oh. You have a visitor, Percy."

He looks up, and smiles broadly when he sees Annabeth. And then he stands up and sweeps her into a firm hug when she comes over to them, his lips pressing into the top of her head, and then gently landing on her lips when he pulls away from the hug.

"Hey," he says gently. "What're you doing here?"

Annabeth swallows. Hard. "Your mum invited me." She's staring at his tutor, in her little summery dress and sleek heels. She makes Annabeth furious. Fuck.

He grins. "That's great. Are you staying over?"

"If you want me to."

He frowns slightly, then. "If I… of course I want you to!" he says, indignantly. "Why would you think…?" he trails off, and then he sighs heavily. "This is Riley. She's my tutor. Riley, this is Annabeth."

Waving at Annabeth, Riley stands up. She's tall and her legs are so long that Annabeth feels self-conscious about her own; especially in her shorts and baggy Camp Half-Blood shirt that's bright orange and ripped. The only thing that makes her feel better is that the shirt is three sizes too big and hanging so low that her shorts aren't visible – which makes it painfully obvious to Riley that she, Annabeth, is wearing Percy's shirt. Okay, so maybe Annabeth had done that on purpose. So sue her.

Riley's smile is wide, she's wearing no makeup and still looks effortlessly beautiful. Her teeth are so pearly white and blinding that Annabeth wonders if she's a daughter of Apollo. All of Apollo's kids are hot; just look at Will Solace.

"Hi, Annabeth," Riley says. She stalks forwards without missing a single beat on those impossibly high heels, and holds out a hand for Annabeth to shake.

Her eyes are sparkling with a kind sort of warmth that makes Annabeth even angrier. Either she's just putting on a front for Percy, or she's actually genuinely a nice person. The second option is worse, mostly because it makes hating Riley harder for Annabeth.

Fucking hell.

The next time she meets Aphrodite, Annabeth is going to turn violent. If she didn't have to love Percy so much, she wouldn't be in this godsdamned mess. Love, Annabeth thinks bitterly, is ridiculous. She's never felt like such an illogical mess in her life.

"Hi, Riley," Annabeth says back. Her tone trembles slightly, but she hopes nobody notices. She doesn't think that they do – she's just on edge and frustrated and gods she needs to calm down. She takes Riley's hand abruptly and drops it just as quickly, her hands clammy and sweaty and most likely disgusting.

The silence that follows is awkward, and is only broken when Percy clears his throat and claps his hands together. "Anyway," he says, voice deep. Has his voice always been that attractive, or is Annabeth just so on edge right now that everything is magnified? And when he looks over at Riley, Annabeth is sure that she must be imagining the slight way that he lingers on her face. Surely. "I need to get back to my homework, Annabeth, but if you want to put on a movie or something?"

Riley smiles, kindly. "I'll only be here another twenty minutes or so, Annabeth," she says, voice placating. Why is she so calm?

"Right," says Annabeth. "I'll be, uh, in your room, Seaweed Brain."

She bolts without another word, ignoring Percy's curious glance in her direction and the amused way in which Riley says; "Seaweed Brain? You two are adorable, Perce."

Perce? Annabeth is two seconds away from strangling this intelligent bitch with her bare hands.

Piper might have been utterly useless the last time that Annabeth called in a panic, but Annabeth is running out of options. She turns on the shower in the bathroom and opens up a well-placed window that makes a dim little rainbow in the spray. Does she have a drachma on her?

She does. There's one that weighs heavily in her pocket.

"O Iris, accept my offering. Piper McLean at… at… Camp Half-Blood?"

Piper is in the training arena, bashing the Hades out of a practice dummy with her fists. Her short hair is flying in every direction, chest heaving with exertion and kaleidoscopic eyes flashing with determination. But she stops when she realises that Annabeth is right there and staring, and a smile breaks out on her face.

"Hey, Annabae," she says. She looks like she's trying hard not to laugh, but Annabeth is too frazzled to reprimand her for the shocking nickname.

"So, I met Percy's tutor."

Piper's eyes widen. She steps around the dummy and closer to the projection of Annabeth's face.

"And?"

"She's hot as hell. I told you this would be my luck. He's probably going to run away with her now and have her children."

The daughter of Aphrodite wrinkles her nose. "First of all, no he won't. Second of all, you need to calm down. Third of all, are you sure that you're not the one going off and cheating on Percy with this girl?"

Annabeth looks distraught. "She's a red head! Like Rachel! And he used to have a thing for Rachel!"

This is literally the most lost Annabeth has ever been. She's fought demonic cheerleaders and Gorgons and Titans, but she can't for the life of her figure out her own love story. This isn't something she can look up in a book, or sort out by herself. Aphrodite made sure of that when she wrote the handbook of love in invisible fucking ink and turned it into her own personal godsdamned soap opera.

Piper nods. "Yes," she says. "I can see how that might trouble you. Percy preferred you, the blonde, over Rachel, and yet he might dump you for a red head that he just met and who teaches him math. No offence, Annabeth, but… math isn't really a good building block for a relationship."

"And neither is telling your boyfriend that he's an idiot."

Shrugging, Piper looks down at the ground and yawns. "If he really had a problem with that, he'd have left you years ago. Now, are you going to go out there and-" she breaks off, looking at something over Annabeth's shoulder before her face breaks into a broad grin. "Bye, Annabeth."

"Wait, Pipes, what-"

Piper swipes her hand through the image of Annabeth and severs the connection, and Annabeth spins around.

Standing by the doorway with his mouth slightly agape and his green eyes stormy is Percy Jackson.

"H-how long have you been there?"

Percy raises his eyebrows. "Something about me having children with my math tutor?"

Great. Just great. Now he's going to know what a jealous piece of shit Annabeth is. She swallows hard, reaching over to turn off the spray. She doesn't offer an explanation, just stands there with her hands dangling uselessly by her sides as she works out what to say to him.

She'd rather face Kelli the empousa again than tackle this.

"Annabeth," Percy squeezes his eyes shut tight, like he's trying to work out what to say. "I don't… I heard the shower start and I just wondered… well, you seemed upset before. And I thought maybe…"

"You eavesdropped on purpose?" Annabeth is indignant. Sure, she could deal with it when she'd thought that he'd accidentally overheard her talking about him having kids with other women but… the fact that he'd come up here with the intent of eavesdropping?

"Well, what the hell else was I meant to do?" Percy looks frustrated. "You don't tell me anything. You've been upset since… since I told you…" he trails off, like he's just sort of working it out. "Are you jealous of Riley?"

"No!" Annabeth snaps. Mostly because, well, he should've really worked that out by now.

"You are," he looks slightly guilty now. "Annabeth… I thought I was doing you a favour. I thought that helping me study wasn't something that you needed to be saddled with. I know I'm an idiot and I don't get stuff straight away, and that maybe it wasn't your job to stress about that."

Which makes it all worse, doesn't it? Annabeth wants it to be her job. And she hates the fact that he thinks so lowly of himself; and she can't help but blame herself for it.

"No, Percy," Annabeth tells him. "I was wrong to snap at you. And… I call you Seaweed Brain because, yeah, maybe you can be a little obtuse sometimes, but I don't think you're an idiot. You might not always get school work, but you're pretty smart when it comes to real life. ADHD and Dyslexia is hard to deal with for me, and I'm a daughter of the wisdom goddess."

He looks like he's about to protest, but Annabeth is on a roll now.

"So, I want you to go down there and tell Riley that she's been great, but you have me now. Okay? I'm going to help you pass your last year at school if it's the last thing I do."

And then she kisses him, lingering on his lips slightly and relishing in the taste of him. The fresh spray of the salt and the smell of the ocean that dusts his skin like a smokescreen.

Then Percy smiles at her, and his nose brushes against hers as he touches her lips with his once more, and he says, "okay."

And months later, Percy Jackson passes high school; and the grin on his face is worth every minute of study (and maybe the celebratory sex is, too).