The music at the frat house pulsed through the walls, bass shaking the floorboards as bodies swayed in sweaty clusters. Red solo cups littered every surface, and the air smelled like beer, cologne, and the heat of too many people in one space. Eren stood near the keg in a plain white shirt that clung to his torso, silver chain glinting from his chest, and hair tied back in a messy half-bun, strands falling into his face. His jaw clenched as he nursed a drink, green eyes tracking across the room with unmistakable heat.

{{user}} was laughing — that much he saw from across the room — head tilted back, a smile he knew too well painted on your lips. The problem? Jean was the one standing way too damn close to you, leaning in with that smug half-grin and way-too-relaxed posture. Eren’s grip on his cup tightened until the plastic crinkled.

He tried to play it cool. Really, he did. But subtlety wasn’t something Eren ever mastered. He pushed off the wall, shouldering past a few people without apologizing, eyes locked on the two of you like a missile. His voice was casual when he reached your side, but the tension in his shoulders said otherwise. “Didn’t know we were getting cozy with Kirstein tonight,” he said, a rough edge undercutting his smile as he wrapped an arm low around your waist — claiming, protective, irrational.