Also known as:
THEORETICALLY KISMETIC.

Disclaimer: (Insert disbelieving laughter here) Yeah, right.

1.—Lock and Key
That's what he keeps her heart under, and despite her expertise at metal structures, Annabeth Chase has yet to get it back.

2.—Walking
He has taken to imagining how perfectly her slim, milky calves would fit against his hands every time he sees her legs moving in her lithe nymph's step.

3. –Breaking
With the weight of the sky strangling her shoulders, straddled across her back, only the thought of his (hopefully) inevitable arrival keeps her from shattering.

4. –Jester
For someone always acting like a goof, Percy Jackson can be surprisingly perceptive. Especially when matters concern a certain Daughter of Athena.

5.—Valiant
Chivalry, Annabeth discovers as Percy hugs her to his chest against the incoming rain, isn't really dead. It just lies dormant and conveniently resurfaces in awkward teenage boys whenever you need it.

6.—Waltz
He steps on her feet at least three times, and at one particular interval she accidentally kicks him in the shin, but when the next song comes up, they smile and get up again anyway.

7.—Breathing
When there's nobody (and he means nobody, not even those trees-that-are-really-nymphs-but-still-manage-to-outrun-him-every -time-creatures) looking, he likes to twine hair around her face and watch them flutter delicately against her pink, silky lips when she breathes in slumber.

8.—Quarreling
They've given up on arguing since they always end up making out halfway through them anyway, and now just go straight to the making out.

9.—Jump
Between her look-before-you-leap-Seaweed Brain! and his I'm-just-kinda-making-it-up-as-we-go-along-Wise-Girl!, they balance each other extraordinarily well.

10.—Jewel
She tells him not to be stupid and how impossible it was, but he's convinced that when she smiles, jewels glint between the gaps of her happiness.

11.—Quitting
A relatively alien concept to Annabeth and Percy which they mulishly refuse to learn, much to Poseidon's and Athena's dismay.

12.—Smirk
Annabeth could tell that whenever a rare smirk wracks his face, something Very Bad and probably Very Amusing (if she wasn't the Unfortunate Victim, of course) was going to happen.

13.—Justice
Watching Annabeth wade into the lake with her bathing suit hugging her curves as she chats obliviously on to some Huntresses, Percy is convinced there is no justice in this world. Then, she smiles, gestures him to join, and he thinks 'okay. Some justice in this world', and proceeds to cradle Annabeth in his arms and kiss her, much to the disgust of certain chaste maidens nearby.

14.—Burning
Then, stifling another blush, Annabeth wonders how that green-eyed, black-haired Seaweed Brain could make her heart throb so furiously against the fires rising in her chest.

15.—Worry
Something you had to do a lot of when your boyfriend was a reckless demigod with absolutely no strategic planning skills but still frequently puts his life at peril on a daily basis.

16.—Balcony
You know he really loves you if he's willing to listen patiently to you waxing eloquent about the structures of Juliet balconies for ten minutes straight.

17.—Wonder
He loves to watch awe splash like sunshine across her freckled face, so innocent and happy it's heartbreakingly gorgeous, especially considering how rarely Annabeth was bedazzled.

18.—Natural
Talk, smile, exchange secret glances, twine hands behind backs—everything just comes together naturally.

19.—Question
Most of her questions to him are rhetorical, such as: 'are you absolutely crazy, Seaweed Brain, or are you just being stupid!?' but he likes answering them anyway: 'No, I just like improvising and taking risks. A lot.'

20.—Neutral
Even though Grover insists he was not going to interfere in any possible way, both Annabeth's and Percy's suspicions are confirmed when he pushes them into the abandoned storage closet and locks the door.

21.—Balloon
They write what they love about each other on pearly, sun-kissed balloons then let them go on windy days, watching until the pair of silver-and-blue wink and disappear into the cloud-plumed sky.

22.—War
Pushing a square of ambrosia onto his lips, you sweep the cap off your head and watch the remnants of war fade from his dusty, blood-smeared face as his viridian eyes crack open.

23.—Sorrow
Thalia sees their heads—one inky black, one angelic blonde—entwine, and her heart reopens painfully as she thinks of the boy with the dragon scar and flame-tipped sword and the what-ifs that could have linked their fates together.

24.—Horizon
In his dreams, Percy Jackson always sees a steel-eyed, butter-haired girl with wisdom and wit flashing like pearls behind her teeth laughing at the edge of the horizon, just out of his reach.

25.—Quiet
They don't get it a lot, but when they do, the quiet is tangible, balancing as delicately as a ladybug on a string in the air as they smile at each other and let the silence speak for what they cannot say.

26.—Sordid
She sees Kronos as black: faithless and minatory, and Percy was white: undaunted and valorous. Luke was grey, whose white was so polluted as he fell into the black. So as war approaches, Annabeth prays to Athena, to Zeus, to Olympus itself that this time there would be no grey.

27.—Serenade
It probably would have worked too, if Percy wasn't as bad at singing as he was at dancing. The fact that his guitar only had two strings and was almost cleaved in half after a mishap with Riptide didn't help. (She liked it anyway, because of how sweet he looks when he blushes.)

28.—Weddings
Between one parent gushing about flowers and dresses and grandchildren (an issue they still can't confront without blushing furiously) and another prophesying an apocalypse should a Son of Poseidon and a Daughter of Athena be joined in holy union, Percy was seriously regretting dismissing elopement as an option. (And after Athena's rant on Poseidon And HIS Kind of Men, he was pretty sure Annabeth was too.)

29.—Whimsy
A shell bracelet made in ten minutes…a makeshift bouquet of autumn leaves…a stone shaped like a lopsided heart with his name on it…the only thing consistent with Percy's random gifts was how spontaneous each of them were.

30.—Nowhere
That's pretty much where every one of their arguments usually end up when it isn't about anything death-defying.

31.—Virtuous
Well, being demigods, having virtue was kind of a given, despite the rumors of what they did when everybody was asleep.

32.—Sojourn
Despite their shared love for traveling (Annabeth: to structural miracles like Hagia Sophia. Percy: to anywhere with salt water), their hearts permanently stay in one place.

33.—Quirks
They find the little things—his affection for various blue confections, the soft tickle spot near her jugular that gets her every single time—just as undeniably attractive as the big ones.

34.—Defeat
"I see it is futile to extend this further." Athena eyes her daughter warily, who determinedly holds the gaze. "Go. Just go." Rubbing her temples, she watches her now-elated daughter jump into the arms of her new—ugh, boyfriend. Poseidon stands behind her, with the same my-kid-will-give-me-gray-hairs expression on his face. "Well, defeat was inevitable anyway." He offers wearily to her. And for once, Athena actually agrees with him.

35.—Belief
He dreams more than anybody she knows, and the immortal hope that never dies (the one that always blazes like the coals in Hestia's hearth) is probably one of the reasons why she loves him so much.

36.—Bias
He tells her she's gorgeous, and she snorts. "You're too biased." Grin. "But that doesn't mean I'm wrong, does it?"

37.—Near
The best part is when he's inches away from her face and she can count every speck of light that falls into his eyes.

39.—Wishes
They wear each other's wishes like ribbons on their finger tips, so whenever there's an opportunity to grant one, they can always whip them out instantly.

40.—Jousting
They exchange witty banter and it becomes a daily joust of words—at least, that's what Annabeth and Percy call it. Everybody else just calls it 'flirting'.

41.—Waste/Wasteland
Percy still blushes a little when he thinks of the resplendent Goddess of Love reclining in her limousine among the desert of junkyard metal and scrapped heaps of waste, talking about Annabeth and anguish and quests for true love.

42.—Soliloquy
Neither of them cared much for monologues. They were more of a punch-the-villain-while-he-was-in-the-middle-of-one type.

43.—Stupidity
It was rumored that Percy Jackson had coined the famed phrase now used by demigods everywhere during one of Annabeth Chase's legendary reprimands about his schemes: 'it's only stupid if it doesn't work'.

44.—Solitary
When he only has his shadow, she's the one who makes sure he never stands alone.

45.—Sarcasm
"Somebody's been brushing up on their botany skills." Mr. D snipes with a rather snarky look festooning his face as they come stumbling back from the forest corner, hand and hand, twigs in their hair and their shirts turned inside out.

46.—Convention
"Percy Jackson." Annabeth stops slashing at the demons with her dagger and instead stares at her boyfriend, her nose wrinkling in disbelief and bemusement. "Did you just propose to me in the middle of the Underworld?"

47.—Share
Annabeth wonders how many times she'll have to sneak away wearing one of His Shirts before his entire closet accumulates in her trunk. (Probably not that many more.)

48.—Nuance
He might not be very subtle, Annabeth reasoned, but his bluntness also made him very, very sweet. (Even if he is dense beyond belief.)

49.—Whiskey and Rum
It's Halloween, and as Percy walks into his fifth tree, Annabeth hides an amused grin and tells him that he should probably remove the eye patch, because pirates didn't go around banging so frequently into forestry.

50.—Time
The boy had whirlpools and riptides in his vivid eyes; the girl carried an infinite playlist of wisdom in hers. She looks him straight in the riptides, comments languidly: "You drool in your sleep", and it starts all over again.

A/N: I just finished my first Percy Jackson and the Olympians fic. Yay me.
Reviews are appreciated, and make me ridiculously happy. Themes taken from unwinding fantasy's 50 sentences ishihime Bleach fic, How to Make a Rainbow, and the 100ThemesChallenge on deviantart.