Adrien is the first to find out.

It happens unexpectedly and without warning, but all at once the pieces fall together and he wonders how he didn't see it sooner: like the dawn sun breaks through a cloudy, sleeping sky.

They are sixteen and Ladybug collapses after a particularly grueling akuma. He scoops her into his arms without hesitation, ready to get her to safety, but they are in a wide open field with nowhere to hide and not enough time to find privacy.

He's holding her in his arms when the last blip of her earrings sounds, so he scrunches his eyes shut as tightly as he can. He feels every inch of the warm, pink light of her de-transformation flood over him — from his fingertips to his elbows to his cheeks.

He will not betray her by opening his eyes. He will not. So he stands, silent, not daring to peek — even though, somehow, he already knows who he's holding in his arms. He's caught her from falling enough times to know her weight; he's spent the last several years bumping her hands, her arms, her knees in class or while hanging out with Nino and Alya; he's spent the last several years feeling her sunshine smile, carrying around her lucky charm like a personal benediction in the sole of his shoe.

He's known ever since the day, months ago, when she called him Chaton as Marinette, and not as Ladybug, and the weight of her voice left his mind reeling for weeks every time he tried to sleep.

"Chat Noir…"

His eyes still don't open. The voice isn't familiar to him, but he's smart enough to guess that it's Ladybug's — Marinette's — Kwami.

"Adrien."

At this, his eyes open, but he doesn't dare look down at the figure in his arms. He stares at the little black-spotted fairy in front of him. His eyes well up with tears — he can't help it.

"It's okay," Tikki says. "You've known for a while now…haven't you?"

Together, they bring Marinette back to safety. Tikki says that he would have found out eventually, and that he could tell Marinette — Ladybug — that he knows.

But he doesn't say a word. The next time they're together, he asks if she remembers anything. She kisses his cheek, and says that she doesn't, but she knows that he saved her. He wants to tell her that she's the one who's saved him — but she wouldn't understand. Not yet.

They are seventeen, and he is so in love that it hurts. He tries his best to act normal, to pretend that he doesn't ache to be with Marinette with every step he takes. But he needs her to love all of him — not just who he is in public, but who he is behind the mask, too — just like he loves all of her. Only then, he thinks, can he tell her the full truth.

It's easier when he's Chat. He doesn't have to hide his affection so much. Marinette passes off his flirtations as "typical Chat behavior" — if only she knew, he scoffs to Plagg on the nights when he can't fall asleep.

But then he gets an idea, and the late-night visits start. He hops onto her balcony and knocks on her trap door, making up some excuse that he's on patrol and needs a drink of water. Next week he does it again, and he cheekily asks for something from the bakery. Marinette kindly obliges, giggling as she hands him a strawberry tart.

Next week, he brings her a present: he noticed that her ears are always red when she walks to school in the cold morning, so he presents her with a pair of earmuffs — his father's brand, of course, a wink to his alter ego that he's sure she won't notice.

He doesn't tell her his reasoning. He just hands them to her and says, "They match your eyes." She hardly says another word to him the rest of the night, but he knows by the light in her eyes that she likes the gift. It warms him from his toes to his fingers.

She wears them to school the next day. He asks — as Adrien — who gave them to her.

"Uh…my friend," she says, tucking a lock of hair behind her ear.

He doesn't miss the blush that paints her cheeks like a fresh bouquet of azaleas. It sends his heart into a dance.

He visits her again — as Chat — the next night, but when he knocks on the trap door, she doesn't answer. He can't help the sinking feeling in his chest. Maybe he was wrong, and she isn't falling for him, after all.

But then she isn't at school the next day — or the next. This time, he comes to her house as Adrien, and he knocks on the front door.

Mrs. Dupain-Cheng answers with a long face, shaking her head in that way that only mothers can master — Marinette is sick and can't accept visitors.

So he returns later that night — not to knock on her trap door but to leave a box of her favorite chocolates, a bouquet of azaleas, and a brand new sketchbook made of pink leather and adorned with red, hand-stitched flowers. He puts a little envelope on top, bearing a note that reads:

"A pink care package for Sleeping Beauty. Feel better soon, princess!"

When Marinette finally returns to school, she doesn't look at him. He wonders if he overstepped a boundary by leaving the gifts for her — but then he remembers that she didn't know it was him.

He approaches her in the hall at the end of the day: "Marinette!"

She doesn't even turn around — just tucks her head down and disappears into the crowd.

He stands there in the hallway, in a sea of people, feeling painfully alone.

He tells himself that it wouldn't be right to visit her that night —she doesn't want to see him, and it isn't right to use a disguise to bypass her wishes. But when he passes by her house on patrol, she's standing on her balcony, staring into the night.

He can hear her crying.

So he swears to himself that if she doesn't want to see Chat, either, he'll leave and never come back.

"Princess?"

She turns toward him, and he doesn't miss how she hastily wipes away her tears.

"Chaton," she says, her voice cracking on the second syllable. But she doesn't miss a beat. "Thank you for the gifts. They're beautiful."

He pounces down from the roof to sit on her balcony railing, as is usual for their visits. They're quiet for a few moments, Marinette sniffling and he wondering how he managed to mess everything up so badly.

"What's on your mind, Mari?" he asks, gently, lowering his voice so that she knows he's sincere.

Surprisingly enough, she laughs.

"It's so silly," she says.

He rubs her shoulder. "I doubt it. You're too strong to cry over silly things."

But he chooses the wrong words, and she bursts into tears again.

He hops off the balcony and pulls her into his arms, resting his cheek on her midnight-blue hair. They haven't embraced like this — not ever, at least, he doesn't think so, and he relishes in the feeling of how she fits in his arms: like a vase fits between two faces, like she was meant to be there, like yin fits with yang.

Maybe she feels it, too, because her tears dwindle away into mere sniffles.

When she pulls away, they lock eyes. Hers are glistening with tears; reflecting starlight like a lake reflects the moon. He's breathless at her beauty, but feels a pang of guilt at the possibility of being the cause of her pain.

"Please talk to me, Mari," he says, and with every word the lump in his throat feels like sandpaper rubbing against wood.

"I — can't," she says, hiccuping for air to fight against her tears.

And tears, like laughter, must be contagious, because her struggle breaks the stone sitting in his heart, cracking it open like an eroded boulder finally yields to a river.

All at once, with both fervent eagerness and an acute awareness for her boundaries, he ropes his fingers into her loose hair and pulls her mouth to meet his.

She melts into him — less like a vase between faces (because they've crushed the vase, now, it's disappeared from the space between their lips because now there is none), and more like two raindrops meeting on the window.

She isn't Ladybug-turned-Marinette anymore — not to him. She's just Mari, and he just loves her.

And when she pulls away, he doesn't hide that fact. He looks at her like she's the moon in the night sky. He couldn't hide it if he wanted to.

She says, "Chat, I have to tell you —"

And he says, "Princess — I already know —"

And she says, "I love you."

And the words vanish from the tip of his tongue.

He blinks at her. "You love me?"

"A-And…And someone else," she admits, biting her lip.

He feels the hope bubble up in his chest, but fights against it — he has to keep his hopes at bay, just in case. Just in case.

"That's why you were crying?" he asks.

She nods.

"Who is it?" he asks, gently, like balancing a pebble on the head of a pin. "Who else, I mean?"

She shakes her head, instead, asking, "Don't you love Ladybug?"

He grins. "I love you, Mari." And then, with a flash decision: "But as far as I'm concerned, the two are interchangeable."

She opens her mouth — closes it. Opens it again, and breathes, "How long…?"

"You called me chaton," he says. "Forever ago. And then…that day, in the field. You de-transformed. But I didn't look, I swear. Not until Tikki told me to, so that we could get you to safety."

Her whole face lights up. "You…you know!"

He nods, nudging his forehead against hers and then resting there. "I know," he confirms.

"That changes everything."

He raises an eyebrow. "How?"

She smiles. "Because I know, too."

He blinks, one-two, like raindrops.

"But how —"

"The earmuffs," she says. "You gave me earmuffs that won't be released in Gabriel Agreste's winter collection until November." She pauses, looks away from him, embarrassed. "And then I…faked being sick, because I was so shocked, and I just didn't know how to…"

"How to deal," he says, brushing her cheek with his fingers. "I get it. I was out of commission for days. You just didn't notice." He laughs. "You know, I literally almost kissed you the first day back from school."

Her eyes snap to meet him. "I remember! Oh, my goodness, I totally remember, you had this look, I couldn't believe —" she breaks off, amazed. "You knew? All the way back then? Why didn't you…?"

He grabs her hand. "I wanted…I needed you to love me. All of me." He gestures lamely to his costume. "Not just Adrien, but Chat Noir, too."

She looks at him with an uncharacteristic sadness in her eyes. "Oh, chaton…I think a part of me always has."

His chest feels like it's going to burst. He wants to crush her in his arms — this lovely, creative, beautiful, smart, funny, kind girl, likes him! Loves him!

He settles for another kiss.

Adrien is the first to find out — but he's never been good at keeping secrets.