It agitates him. More than he can explain, express or put into words. The fact that he's agitated agitates him, and it's also that it's over you makes it even worse.

He'd thought that a thorough workout would clear his head—Rin Itoshi lived and breathed soccer, and you certainly weren't soccer. Though, you do smell good. Wait, what?

And of course, seeing you right around the door makes him want to throw the barbels at your stupid face. "Out," he hisses.