Responses
Because some kids aren't exposed to homosexuality or haven't figured out their sexuality yet. It's very normal for young people to not have an answer. Some of us didnt know a guy can date/like another guy until we're old enough. Though this depends on the community you grew up with.
Only read chapter 1. I don't understand why the MC can't just say he doesn't swing that way. I mean, isn't that the most normal answer to give? BL mangas/mahnwas that has this kind of situation where the ML confessed to MC and where MC never really had any interaction with ML never ever give the most common sense reaction. Like, why can't you just say that you're not gay? Why complicate things? It's kind of irritating. It's like they're not using their common sense just so there could be a story. （￣へ￣）