You're thinking Western. He's Japanese. Maki's already being disrespectful (as I understand their culture) by trying to pry into his father's business.For one thing, great way to build trust with your teenage son. Yeah, he's not legally obligated to answer his questions about who he's seeing and why they got divorced, but he's a shitty dad if he doesn't, in my opinion. Secondly, even if he's not gonna tell him, it's still a fucking asshole thing to just ignore him, pretend not to hear him and walk out. If he intends to keep it secret for whatever reason, he can just use his mouth and explain that.