Aoi translates fear to anger. It's his automatic reaction to being scared. And he's so afraid that Duster's gonna start laughing at him any second now. His eyes narrow, though his flaming cheeks probably make it look more ridiculous than intimidating.

"HEY, nobody made you come. You coulda said 'no', or gone with someone else. But you didn't. So, yeah, either it's a date, or else you're a dumbass who does romantic shit with his friends. And...that's fine...but...I gotta know which it is..."

He loses steam as he finishes, because he's pretty sure Duster's gonna run for the metaphorical hills and leave Aoi up here alone with the fireworks. Who's he trying to kid? Why'd he think this date thing was gonna work?