He should probably have figured that something was up the first moment he saw them together.
It was nothing special-- not really. They were just holding hands in front of their next class, a totally normal couple-y thing to do.
Except, he hadn't been aware that they were a couple.
And for some reason, he can't work out why it buggs him so much that they are.
In class, he is distracted-- he can't stop staring at her, trying to gauge if she looks like a girl who's dating an artist. Is there a specific way she should look? Is he reading too deep into it? They were just holding hands, after all. It's not like they were making out or anything.
Why should he care, anyway?
It's not like he likes Marinette in that way. Why should it matter if she wants to date Nathanaël?
He can't see much that's different about her-- just that she looks so happy. Like she's floating on a cloud or something. The teacher yells at her twice for staring into space, and while that's nothing new, he can't help but connect her behaviour today to her newfound attatchment to Nathanaël.
It shouldn't matter, he decides. He has Ladybug, after all, and even the thought of her puts a smile on his face. He's impatient for class to finish so he can go home and see her, right? That's why he's desperate to leave the room. Not because he can't stand the looks that he knows Nathanaël is giving her from the back of the room.
Either way, when the bell goes, he's first out of the class, and he gets home quicker than he ever has before.
It's because he wants to see Ladybug, he tells himself.
But that night, on patrol, Ladybug herself is acting like a punch-drunk teenager. She keeps staring off into space (like someone else he knows) and going blank when he speaks to her. Frustratingly, there are no colourful villains to fight that night-- which is a shame, because after the day he's had, he could really have done with punching something orange.
He comes into school optimistic the next day. New day, clean slate, shiny new Adrien. No need to obsess over anyone.
This attitude is shattered the moment he sees Marinette perched on Nathanaël's desk.
He spends the rest of the day watching them laugh and smile at each other and-- on one inexplicably sickening occasion-- even cuddle.
He returns home in an even fouler mood than yesterday's, and when Ladybug is just as giggly and vague as she was the previous night, he bails from night patrol early-- leaving the girl he's supposed to be in love with slightly confused and more than a little hurt.
And yet again, he lies awake and wonders; why should it matter to him what Marinette chooses to do? Why should he bust a gut over the fact that she's kissing someone that isn't him? Why is it that, when he sees Nathanaël around school, he wants to say something nasty and mean and totally out of character for him?
When he does get to sleep, he dreams of Nathanaël kissing Ladybug and smiling at him smugly.
"Are those two dating?" He gestures to the only two students who are talking anywhere near animatedly in the classroom.
"Well, yeah. I thought everybody heard." Nino sounds uneasy, as though he's not happy getting the words out.
Well shit. Was the entire school in on this before him?
"Hey, Adrien?" Yet again, Nino sounds hesitant.
"Why are you scowling like that?"
He can't answer.
"You're doing what now?" If Plagg could sound any more irritated, Adrien would like to hear it.
"I said I'm skipping patrol tonight."
"For the second time in a row? Gee, you're really laying it on thick, aren't you?" The kwami returns, voice laced with false sympathy.
"What are you talking about, Plagg?" Adrien says quietly from his bed.
"I mean, you're hardly the first guy to get hung up on a girl, buddy. Happens to everyone. You just gotta get your butt in gear and power past it."
At this, Adrien raises his head.
"Who says I'm hung up on Marinette?"
"Are you really going to be this opaque? Adrien, you should have figured something wasn't right the moment you first saw them together."
Unsurprisingly, he does end up going on patrol that night.
The only difference is that Ladybug isn't there.
He's standing at his locker. He has been for eight minutes. Somehow, for reasons he doesn't want to think about, he can't move and he doesn't want to-- despite the fact that school finished nearly fifteen minutes ago.
"What is wrong with me?" He murmurs quietly, shutting the locker door and beginning to move away. Just as he reaches the door, a conversation drifts through from outside in the hall.
"I told you this was a bad idea. C'mon, it's been a week and nothing's happened. Let's just call it off."
He's ready to dismiss the conversation as nothing but a lover's spat, but then the second speaker begins.
"I'm telling you, it's working. Have you seen him lately? He barely speaks to anyone, even you."
Wait a second.
Are they-- are they talking about him?
"I don't know, Alya. It's putting a lot of strain on Marinette and Nathanaël. Plus, how are we going to explain a sudden breakup when they've been looking so happy all week?"
Ok. Something is definitely going on here.
The second person-- Alya, by the sounds of it-- tries to continue ("Just give it two more--") but he pushes the door open before she can finish.
Nino and (yes, he was right) Alya stand, looking equal parts shocked and embarrassed, in the hall together.
"What the hell is going on here?" Adrien asks, his voice rising dangerously high.
"I... I'm sorry, Alya. I can't do it anymore." He turns toward Adrien. "Dude, I won't lie to you. Nathanaël and Marinette aren't really dating."
Why exactly does this make him feel happy? Surely he should be confused? Right?
He manages a: "They-they're not?"
But Alya says, "Look, don't get mad at Nino. It was my idea. It's just that... Marinette's felt really strongly for you for a while now, and... well, God, Adrien, anybody can see that you like her too, so I thought... I thought if we made it look like she and Nathanaël were dating, it would finally make you jealous enough to expose your true feelings and shit and... I don't know... I guess it didn't work."
Nino rubs the back of his neck self-consciously. "I said it was a bad idea form the beginning."
Adrien has been silent the whole time.
"Adrien?" Alya tries, "Look, we're really, really so--"
"It was a lie?" He cuts her off. "The whole thing? A lie? They were never really together?"
They both stare at the ground, guilty.
"Yeah. Actually, Nathanaël's been seeing this really nice girl outside of--"
"Where is she?"
Alya stops, then starts again. "Who, Marinette? She and Nathanaël said something about going to the library after school--"
Adrien is tearing off before she can finish. He just hears her say to Nino, "When will you learn that all of my ideas are good ones?" and then he's gone, running towards the library like his life depends on it.
He catches Nathanaël leaving just as he rounds the corner.
The red-haired boy smiles. "Good luck, dude."
"Thanks." Adrien nods, and sprints through the doors.
And there she is.
The girl who's driven him mad for a week, the girl he never even realised he cared about, the girl he came so close to losing, and for once in his life he knows what to do.
She looks up just in time to see him sweep down and kiss her, passionately, as he wraps his arms around her like she's something sacred.
When he pulls away, he breathes her name gently.
"I fucking love you."