Summary
No one knows how it actually started... Or who initiated the whole mess of limbs they were entangled. It was raw, pure lust.
No, not only lust. It was more. It's always been much more than that.
Long after the last war, life happens. And demigods discover why love is the root of everything.

Chapter 1

No one knows how it actually started... Or who initiated the whole mess of limbs they were entangled. It was raw, pure lust.
No, not only lust. It was more. It's always been much more than that.

Love, affection, care appreciation, devotion... Zeal. A mix of feelings intertwining the heroes in a web they, somehow, knew it's always been there, glueing them together, making them whole. They weren't single entities... Separated... Not anymore. They were one.

Mouths found tongues, lips touched, hands travelled through each other's bodies in a frenzied discovery of skin, feeling, touch, emotion.
Exploring.
Teasing.
Groping.
Feeling.
Making them gasp, moan, laugh and yell in pleasure.

One may say they might have blamed the alcohol (like many people do). One might and will be wrong.
It was never the inebriating liquid. It was their lives pushed together.
Sure, the beverage was sometimes there, but they can attest it might have had only lowered their inhibitions.

It was the regular New Years party at the flat Jason, Piper, Annabeth and Percy shared. People telling stories, sharing moments, remembering feats and why not, counting scars. They were demigods after all. And their lives have never been an easy one.
Take the apartment they were celebrating for example.

Piper actually never imagined the life she's been having. She'd never had imagined how happy and complete their friends make her. Not when she first set foot in the flat.

First it was the loneliness. Tristan helped his daughter buy an apartment in Manhattan. A good one.
She wanted something simpler. He insisted on giving her comfort.
She complained, but in the end accepted it. However, after a few months of novelty, the space she called her home felt too big... too cold... too lonely. Even with her friends popping up and sleeping there more often than not. Piper's flat was some sort of "cheap homey hotel" for them. Then, the first toothbrush found its way to the bathroom.

People might think it was Jason's.

It wasn't.

Annabeth needed a place to stay during her classes at NYU and the daily commute was stressing her a lot. Piper's flat was closer, better and cleaner than the hostel. Or the student's official lodge.
And it was way better than bothering Sally and Paul (or even Percy) for weeks. Surely they didn't care. But Annabeth did.

Life went on fine for a while. Then, Tristan died on a plane crash.

Piper was devastated.

Piper's mom appeared in a golden glow of bright light the second she sensed her daughter's distress over her loss. Piper was speechless. Annabeth, incredulous. All the demigods in the living room, stared, flabbergasted while Aphrodite just looked at her daughter and opened her arms. Piper flew to the goddess' embrace, red faced, eyes full of tears. She felt the love and the comfort only a mother could provide, for the first time in her life.

And so, the second toothbrush found its way to Piper's bathroom.

Jason couldn't come up with stupid excuses anymore. Excuses he gave himself (and anyone who asked), that, in fact, we're only that. Excuses. Because Jason was afraid of actually growing up. He knew the moment he started living with Piper other commitments would follow, and most of them he thought he wasn't ready for.
But Piper needed him. She needed him much more than ever, and even when she had her best friend sharing his girlfriend's apartment, it wasn't the same. Piper needed another type of comfort. One that Annabeth couldn't yet provide.

It didn't take long for the third toothbrush to find its way to the apartment.
Seaweed brain he was, Percy took a long time to figure out that Annabeth's home was Piper's home; and to an extent; his and Jason's.

No, they didn't have anything remotely similar to a four-way relationship. They just shared the living costs. It was an excellent way to keep up with the high bills and scores of having a nice place to call home in the overpriced NY.

Each couple had their own bedroom. Of course, much had changed since Piper first decorated her flat, but now it wasn't only hers anymore... and the walls, furniture, appliances, mess, clothes and lives reflected that. In a few months; the too cold, too big, too lonely apartment wasn't like that anymore. It was full of life, talk, fights, laughter. It was their home.

They shared the housework (more often then not, they fought over who would do what), the bills (somehow they were balanced on that... "Thank you Wise Girl", they would repeat over and over), the responsibility (sometimes the killing of some nasty intruders too) and their lives, but not their beds or their sex lives. Or their feelings.

Pfft.

How wrong they were.

The first months were the most complicated ones. Not because sharing with four different people was difficult (it indeed was!), but because four powerful demigods in one place called too much attention.

Jason insisted they move out at first. Percy agreed.

Piper didn't talk to them for a week (Jason slept in the couch for longer than that) and she would continue the silent treatment (Jason's punishment included) if Annabeth hadn't made the airhead and the seaweed brain see reason: this flat was the only thing Piper had from her father.
It was his last gift for her, all the rest had been sold to pay expenses (and debts, loads of debts) the actor had left behind.

When Annabeth finally explained everything, they were silently looking abashed. Staring down, completely ashamed.
Contrary to reason, Percy is the first one to verbally apologise. Jason soon follows. And all four hug and cry, saying how sorry they were.
It was then they should have understood they were actually married to each other. But they didn't.

Nonetheless, the monster problem was only mitigated when Ares suddenly visited them.

Yes. Ares.

It turns out Aphrodite cared more for them than they realized and the goddess bullied her lover into working with his father, his uncle, his sister and Hecate into weaving some sort of protection for their flat.

Luckily Percy wasn't home when the war god visited and after doing what Aphrodite insistently pegged him, he left grinning, saying the goddess was mean.

Nobody understood why.

This is 'unbetaed'. English IS NOT my first language, I'm trying my best here.

I've been toying with this idea in my head for quite a while and only now I could finally write.

Spoiler alert: This polyamorous fanfic WILL be about 5 people. :)