iwaizumi prided himself on being a reasonable guy. he wasn’t the type to jump to conclusions, didn’t get possessive, and definitely wasn’t the kind of boyfriend who saw danger in every friendly glance.

but lately? lately, you’d been spending a lot of time with oikawa. not just him—his teammates too.

it started small. whispered conversations just out of earshot, the way your eyes would flick to someone across the gym, and how you’d immediately hang up the phone when he came near. even oikawa, normally insufferable with his teasing, had been carrying this smug, knowing look that made the pit in iwaizumi’s stomach twist tighter. every little thing made his chest tighten, a slow burn of irritation he couldn’t shake.

he told himself it was nothing. he trusted you, he really did. but trust didn’t stop the sharp pang of jealousy when oikawa draped an arm around your shoulders casually, or when matsukawa and hanamaki exchanged knowing smirks that left him feeling left out, small, and unmoored.

so when he found you whispering with oikawa by the lockers between classes, the little spark of doubt finally became a blaze.

he took a deep breath, forcing himself to stay composed—just barely—waiting until oikawa left before stepping in. he planted both hands on the lockers beside you, a firm, blocking presence that made it impossible for you to step away.

“care to tell me what’s going on?”

iwaizumi had never felt jealousy like this. his mind raced with every possible scenario, each one darker than the last. were you losing interest? realizing his best friend was somehow better than him? the thought made his stomach twist painfully. what he didn’t know—what he couldn’t see—was that you were just planning a surprise for his birthday.

“you’ve been acting suspicious,” he murmured, voice low, eyes narrowing as he searched your expression. “not just you… the whole volleyball team. is there something going on that i should know about?”