You
It wasn't quite a party, and definitely not a ball.
Sebastian didn't have much experience with either — his birthday parties were always quite modest, featuring his sister (who, of course, shared it with him), Ominis and, more recently, her in a simple night in the Undercroft with Gobstones games and a cake the two guests bought for the twins at Honeydukes — and thus was quite surprised not at only the grand quantity of students cooped up in a room, but also at the way they danced. There was no grace in their movements, jumping around, hitting each other, and definitely no sobriety left.
His eyes scanned the ambience, looking for his friend among the hordes of drunk adolescents surrounding him, and stopped right at the far right corner.
He saw red.
Sebastian had never thought of himself as the jealous type, at least when he was with Ominis: he had no problem with Garreth Weasley interrupting them to ask his boyfriend a favour, or with Poppy holding his hand when he didn't have his wand. And yet now Sebastian's blood wasn't just burning for her; it was boiling, throbbing under his skin like an infection.
She was pinned against the wall, giggling and smiling up at a stranger, who in turn leaned down every so often to whisper in her ear, his hand quite inappropriately rubbing at her waist. She held a cup and took small sips from it as the boy slowly brushed his lips on her cheek, moving down, down until he reached her neck. She closed her eyes with a lazy smile when he touched her, and Sebastian felt his organs shut down as it took root.
And he couldn't take it anymore.
"Excuse me."
The two jumped slightly at Sebastian's sudden appearance, and he felt uncomfortable at the realisation that she was so preoccupied she didn't even see him approach.
Without waiting for an explanation, his hand found hers and he guided her behind him as the other boy scowled. "What do you think you're doing?"
"I'm taking my friend home," replied Sebastian curtly, trying to ignore how warm and soft and perfect her hand felt in his.
"We were busy—"
"Not anymore." He dismissed him with a nod. "Move along!"
The boy seemed to be about to retort when she clung to Sebastian from behind with the biggest grin on her face. "Seb!" she sang. "You made it!"
The stranger scowled indignantly as she seemed to completely forget about him, downed his cup and walked away, muttering something under his breath about 'being led on' and 'women being—' something Sebastian wouldn't dare repeat and that frankly made him want to run after him and break his jaw. She stopped him by hugging him tighter. And his blood caught fire again, her delicate hands feeding it with soft touches and grasps at his torso.
"Are you all right?" he managed to croak out. "Too drunk?"
"Not drunk," she grinned again. "Happy."
"Happy? Why?"
"Because you're here."
Air left his lungs in a quick and painful attempt to escape the fire. "H-Happy to see you, too."
"Are you going to stay? We're having so much fun!"
Sebastian struggled to turn around in her arms, and maybe he should have just stayed where he was, for his own sake if not for his heart's. The girl's smile widened once she realised she could lay her dizzy head on his shoulder, and she slid even closer into his arms.
Burning leads to melting. And that's exactly what Sebastian's body did, once he was sure hers would catch him.
"You're warm," came her voice, muffled in his chest, his own head hung low against hers in a gentle embrace. A smile pulled at his lips when her scent filled his lungs, and he tightened his arms ever-so-slightly around her smaller frame.
"Are you cold?" he quietly asked, brushing his lips against the conch of her ear and making her giggle.
"Not anymore."
His heart fluttered, and he rubbed a hand through her shoulder blades to feel her more. She was warm, too. And soft against him.
It didn't seem like the party would reach its end anytime soon, and despite his promise to Ominis to pick her up 'at a reasonable hour', she was swaying with him, and he was swaying with her, and they were moving slowly to the fast paced music, like they were the only two people in the world. And she was embracing him, and her lips felt tender on his shoulder, and she had asked him to stay.
"Have a drink with me," she said quietly, so quietly it was a miracle he had heard her over the music. But maybe his body seeked her so much he'd hear her everywhere.
"All right," he whispered just as quietly; she didn't seem to hear.
And so, he guided her, and took a drink for himself. And then another, because she asked him again, and he could never deny her. And another still, because she got one for herself, and he couldn't let her drink alone.
"Thank you," she smiled, glowing in the bright light of the room. But was there really so much light in the room, or was it just her presence that seemed to smoulder and blaze his mind out of conscience, out of existence even? Sebastian didn't know.
"Come here," he dared, and she just laughed. And she was in his arms again, and he wondered — just wondered, not daring to hope yet — if she felt like he was glowing, too.
She was swaying again, and her body pressed on his, her perfume filling his nose like a drug. And perhaps he could let himself hope, just a little.
"I like you." The words escaped him without control, without restraint. There were no chains around his heart anymore, and the bruise that was still harbouring his chest left his feelings free to escape him whenever. And maybe there was panic in his heart, too, an irrefragable fear of her next words, but before that could leave its cage as well, she held his heart again, keeping it in place.
"Really?" she whispered with a lazy giggle, and held him closer. "You're the best."
He didn't know what that meant. And he didn't know if she understood what he meant.
"She doesn't love you, you know that, right?"
"Wanna dance?" she said jauntily, and, without waiting for an answer, she moved again, pulling him in the midst of the crowd. Her arms found their way around his neck, before she whispered again, "waist."
He froze, hands shaking as he slowly brought them to her flank.
"Y-You're not wearing a corset?"
The softness of her waist melted under his fingertips, caving under his grip. He imagined she let him touch her just there, trace the space between her delicate ribs, slowly skimming over her silky skin, apply the gentlest pressure on her stomach where that supple womanly pouch met her hips.
"Too uncomfortable." She closed her eyes and leaned on his shoulder, lips grazing his neck. His arms twitched around her and brought her closer. He breathed heavily in her hair.
Sebastian was starting to feel dizzy, both from the sweet scent of her and the alcohol running through his veins. His head was spinning and it wasn't such a bad idea to lean in towards her anymore. His lips found her cheek in a gentle kiss.
She laughed, and he felt her breath on his face, and then she nuzzled him, arms tightening around his neck.
"Not too drunk?" she asked softly, with small kisses on his jaw that grazed the line between friends and more, but never crossing it.
"N-Not drunk," replied Sebastian breathlessly, a shiver running down his spine, finding home in his lower stomach and stirring his loins. "Happy."
"Happy, why?" Her red lips smeared against his skin, rendering him dizzy and breathless and hers beyond measure.
"Because you're here." And the implication wasn't lost on either of them when he held her tighter.