"So why are you here?" Oikawa asked taking a bite of his salad. "We're not friends."

He paused, studying Sugawara. "In fact, I really dislike one of your juniors." He took another bite. "Don't know why," he lied, he's pretty sure he does. "He must have done something really awful to me."

Pressing buttons is how Oikawa tests those around him. He's usually low key about it. He's not going to bother now.