It was no secret that your younger sister—just one year beneath you—had always been jealous of you. Of how you looked, the way people gravitated toward you, your place in Slytherin, your confidence. And especially your relationship with Theo.

Instead of being happy for you or working on her own life, she spent most of her energy trying to take away from yours. It never worked, but that never stopped her from trying. You’d spent years trying to be patient, trying to guide her, support her—but the truth was, you were tired. Tired of playing the understanding older sister to someone who clearly didn’t want to grow up.

What stung most was how obvious her obsession with Theo was.

You and Theo had been dating since fifth year. It was a slow-burn romance that turned into something real—something solid. He loved you, and you loved him. Everyone could see it. Everyone except your sister, Hazel.

Hazel had been in fourth year when you and Theo got together, and her crush on him had never faded. If anything, it had gotten worse. She went out of her way to talk to him every chance she got, practically throwing herself into conversations he didn’t want to be part of. At first, he tried to be polite, but now? He avoided her like the Black Lake on a stormy night.

⸻

It was a quiet Friday evening in the Slytherin common room. The fire crackled low in the hearth, casting warm orange light across the green velvet furniture. You were curled up next to Theo on the couch, his arm draped casually around your shoulders, his fingers idly tracing circles along your arm. He always had to be touching you—whether it was your hand, your waist, or the way he always pulled you into his side when sitting.

You were sitting with Mattheo, Enzo, and Pansy, laughing at some ridiculous thing Mattheo had just said. The mood was relaxed, light. Theo’s laugh was soft in your ear, warm and comforting.

And then… Hazel walked in.

You saw her the moment she entered—bright smile, perfectly styled hair, and that calculated confidence she wore like a mask. Your stomach sank. You forced your usual polite smile into place, preparing for the interruption. She spotted your group instantly and made her way over without hesitation.

“Hey guys!” Hazel chirped, her smile wide as she approached—but you saw the way her eyes zeroed in on Theo and stayed there a beat too long.

Mattheo forced a smile and nodded. “Hey, Hazel.”

Your other friends followed with similar muted greetings. They didn’t care for her—no one did, really—but they tried for your sake. Sometimes.

Hazel glanced around for an empty spot, and finding none near Theo, she plopped down directly in front of the two of you, facing the couch like she belonged there. You immediately felt Theo’s grip on your shoulder tighten slightly.

“So,” she said, too casually, “what are you guys up to?”

Her eyes flicked to you briefly… but landed on Theo again. Her gaze lingered like she was waiting for him to answer, completely disregarding the fact that he was pressed up against you.

Theo didn’t answer right away. Instead, he looked down at you, kissed your temple with a pointed softness, then leaned back slightly.

“Just enjoying the company of my girlfriend and our friends,” he said, cool and measured, his tone wrapped in quiet warning.

Hazel’s smile faltered just a little. Just enough for you to see it.