She loved him.
She promised herself this as her eyes slid over to her partner, and her lips unwilling turned upwards until laughter spilled out—
She was in love with Adrien Agreste.
Her heart could never belong to another.
He loved her.
From the moment he first saw her trip and fall in his arms, and the second her blues eyes captured his gaze—
He was in love with Ladybug.
He really couldn't see anyone else.
It was all too obvious, as the years went by and the two grew up, that the loves of their lives didn't feel quite the same way.
She saw him every day at the office, and though he beamed at her like the sunshine every time, she realized he only loved her like that in her imaginations—she realized that if she ever thought he loved her like that, it was because she loved him like that.
And a little bit of spring left her step.
Sometimes they would sit under the stars, and their eyes would meet, and she would laugh. That hurt more than anything—her laughter was so beautiful. And it rang out—she didn't love him. If he'd ever thought she loved him like that it was because he loved her… so much.
And sometimes she tried to move on—sometimes he tried to move on.
Dates with other people—she'd tell Chat, and he'd tell Marinette.
Neither noticed how the smiles dimmed on their own face and their loves.
It always failed—the dates, the getting over themselves and each other.
They should tell each other…
"Adrien… (I like you, I love you, I live because of you…) here, your tie's askew, let me fix it."
"M'lady—(You're the sun, the moon the stars; you make life worth living, would you mind if I kiss you…)pound it?"
And they never moved on
They never confessed
Until—well, no.
They didn't.
It was Alya, with her only-so-much patience—Nino with his pity— her parents, who knew better—and most of all, Plagg—yes, Plagg.
People who took them aside, apart, together, trying so hard to show them what was in front of them.
And Plagg.
One stormy night, after a hard fought battle, and they were both home, exhausted, without each other, feeling the pain—And Adrien realizes Plagg is missing.
He can't very well call Ladybug, so he calls Marinette.
So… he's tired, and not thinking clearly and she sounds like his Lady, and she is his Lady, she picks up and she understands
2:30 in the morning, Marinette, not really awake, wonders the streets of Paris, drenched to the bone with Adrien mumbling something on her phone, and a petty black kwami clutched in her palm.
They bump into each other, accidentally, knocking each other over, in front of the Eiffel tower.
And it wasn't so much that they said anything, but that they looked at each other and knew.
And it was never the same after that—in the best way possible.