It started with a kiss.
"Marinette Dupain-Cheng!" Alya's firm scolding made Marinette wince as the taller girl backed her into a corner. "I can't believe you! What were you thinking?"
"Nettie..I…" Chat's firm grip on her chin, breath hot on her face as he had leaned in, their lips barely brushing.
"Alya, it's not what it looks like!" Marinette pleaded, backing towards the utility closet. The hallways were bare, the other students having made their way to their classrooms only minutes prior.
"You kissed him! Right here! In front of everyone! Do you think Chat won't find out?"
Adrien's smile as he had leaned in, his kiss on her lips a habit, a reflex. And then she'd kissed him back.
"No, I-"
"Why were you even with Chat last night anyway! I thought you were in love with Adrien?" Alya's finger prodded Marinette in the chest and the younger girl frowned, brain fumbling for an answer.
"I…Chat's waited years for my attention. I just-"
"Ladybugs attention." Alya corrected, the seething tone of her voice a warning.
"Well I'm Ladybug, aren't I?" Marinette answered. It was the wrong thing to say. Alya's anger at her best friend tripled as she stared, unbelieving.
"Are you going to tell him who you are? Either of them?"
"Alya, I can't, I-"
"I'm done trying to win Ladybug's affection!" He'd yelled, kicking aimlessly at a loose piece of concrete. "She and her mystery guy can ride off into the sunset together for all I care."
"Oh Chaton." She'd whispered, wrapping her arms around his neck as she led him toward the trapdoor. She had planned to comfort him with a movie, some snacks..she'd had no idea that they'd end up-
"No! I can't tell them yet. Either of them."
"Well why not!" Alya practically growled. "Don't they deserve to know? Doesn't Chat deserve to know?"
"But you Nettie, you'd never keep a secret from me." Chat had whispered as his lips had collided with her neck.
"Never." She'd repeated back to him, mouth forming the words before she could think them through.
"I just can't, Alya. You don't understand." Marinette pushed past her friend and stormed towards their classroom, taking the stairs two at a time in an effort to evade any more questioning.
"I think I understand plenty." Alya called from the bottom of the staircase. "You're stringing him along! You were just waiting for Adrien to return your feelings, which is obviously happening, and now you'll just leave Chat high and dry. I can't let you-"
"No! Alya, for God's sake, you know me. I wouldn't do that. You just don't know what I know and I can't tell you-"
"Can't tell me?" Alya nearly laughed in response to the overwhelming anger coursing through her. "I thought we were done with secrets, Mari. For once I thought you were sharing everything with me and now you're hiding things again? Why did I ever want to be your friend? I can't believe you would-"
"Adrien is Chat Noir!"
"Oh, really?"
Marinette nodded once.
"Shit!"