"How many times have we done this, chaton?" Marinette mused, gazing out at dawn breaking over Paris.
They stood on the uppermost deck of the Eiffel Tower, not perched brazenly on the tip like teenage superheroes, but safely ensconced behind the railing and protective fence.
"Never enough times, m'lady."
Adrien leaned on his forearms, looking out over the city.
Marinette took him in.
His tie and shirt buttons and cuffs were loosened and rolled, and he'd sighed with relief when he undid his perfect coif with a ruffle of his fingers.
Marinette loved seeing him like this. Not just when she undid him in the bedroom, but when all the formality rushed out of him in a gust, leaving Adrien Agreste™ behind for the person she knew and loved, a nerdy, kind, silly person who looked on things with earthy delight.
She wondered if, over time, anyone else would see this part of him, and a tinge of both joy and jealousy tugged at her heart.
She felt so full – a night out with her love, in their city, to make her dream come true, for here, for now, for...ever. Paris was hers. New York was hers. Adrien was, finally, unstutteringly, wholly, and most certainly, hers.
Almost.
"Marry me, Adrien."
Adrien blinked out of his reverie and did a double take.
"What?"
Marinette stepped closer to him, taking his face in her hands.
"Marry me, chaton," she croaked through sudden tears. There was a long pause as recognition dawned in his eyes.
"Good God, I love you." Adrien gave her a sweet kiss and then drew back, chuckling to himself as he reached into his jacket pocket.
"Yes."
He opened a very small box and placed it in her hands. A small pink diamond winked up at them.
Marinette gasped, looking from the ring to Adrien's face, her expression one of utter surprise.
"How did you –– when?! Oh my god, Adrien, this is––!"
She cuffed him on the arm, hard.
"You sneaky bastard! This is my grandma's ring!"
Adrien Agreste threw back his head and laughed. He laughed from his toes, joy bubbling up in him and refusing to be held back. He laughed, and then crushed Marinette against the railing, wrapped her in a huge hug, and kissed her, and kissed her, and kissed her.
"Hsmssss," Marinette struggled out, her face still glued to Adrien's, their kisses hot and sloppy and happy and unrelenting.
"Hmm?" Adrien asked, his dopey face smeared with the last of Marinette's saucy red lipstick. His eyes were starry.
"Christmas," Marinette panted. "I don't want to not be married to you any longer than that."
Adrien kissed her again, long and slow.
"I'm going to marry Marinette Dupain-Cheng on Christmas morning." His voice was a sweet rasp against her lips.
They smiled into each other, wrapped up in the dawn light at the top of Paris, until Adrien's stomach gave a loud growl.
Marinette giggled and took his hand.
"Come on, I know a great bakery near here."
...
sorry for the formatting problems!