During a physical education lesson, their teacher divides them into team Chat Noir and team Ladybug.
Chloe starts her usual bollocks, only this time Mari resolutely stomps over to team Chat Noir and CREAMS the others, even though Adrien and Kim are there.
Proudly stating no-one was besmirching Chat’s name in front of her, she leaves the class with the strong impression that they never want to get into fisticuffs with her. And that she has a crush on Chat Noir.
Adrien is suddenly struck by how PRETTY she looks when she’s all flushed and breathless from beating the crap out of him.
That night, he goes to knock on her window, with every intention of letting her down slowly. She ends up beating the crap out of him instead - at video games.
He tries again a week later - because he wants to let her down gently, not because he wants a rematch - and instead she feeds him cookies from a piled plate she mysteriously has in her room. Like she was waiting for him.
Third time, he’s sure he’s going to do it because it’s gone on long enough and he can’t keep avoiding it, and instead he finds her crying over her physics homework because she missed the class and can’t understand it. He ends up tutoring her, and comes again five more times at least to help her with her work. She makes sure to have at least one quiche ready when she finds out it’s his favourite.
By the twentieth time he goes, he swears he’s going to tell her, he loves ladybug and only her, if nothing else because he can’t stand Plagg and his teasing anymore. Instead he finally notices the wall plastered with his face - both of his faces. Adrien and Chat smile down at him and he’s not sure how red he is, but it’s VERY hot in her room all of a sudden.
When she notices that he saw and starts blushing and stammering, Chat is a gonner, because this really sweet and talented girl looks both of him in the face every day in her room with admiration and affection and there’s only so much a teenage boy can take.
He talks it out with Ladybug. She appears all surprise at first, a bit embarrassed that she’s always taken his flirting as a joke, but totally ok with the fact that he’d sort of moved on to Mari without realising it. She falls off the roof when he insists that he WILL tell her his identity, because Mari has him on her wall with and without the mask and he wants at least one person in his life who likes all of him like that.
He’s sure she’s hit her head because even when she comes back up, she only speaks in squeaky, broken sentences. She insists on going home right after, and he lets her end patrol early.
He’s not sure what happens the next day when Mari jumps into his arms, calls him her kitty and plants a long, wet kiss on him on the school stairs, but he’s not complaining. He could swear his driver is snapping photos. He sure hopes Gorilla plans to share.